Nice links and between the two I've combined them into a Tosogu listing
I've left the sword info at the end for those interested
Started on 12/09/1948 until May 1982 (Showa 57. Kicho means "precious" and the literal meaning of nintei-sho is recognition in the form of calligraphy. This type of NBTHK paper is commonly called a "white paper". This was the only rank issued until 1950. After that, it was issued as the rank below Tokubetsu Kicho.
Tokubetsu Kicho Nintei-sho
Started in March 1950 until May of 1982. Tokubetsu Kicho means "especially precious". It was the top rank until the Juyo paper was introduced in May of 1958. This type of NBTHK paper is commonly called a "green paper". The green paper and the round seal bearing the kanji of "Toku" was first used on Tokubetsu Kicho papers starting in July 1950 until 1982. On September 1st, 1973, the Koshu Tokubetsu Kicho paper (blue paper) was introduced and was issued as a rank above Tokubetsu Kicho but below Juyo.
Koshu Tokubetsu Kicho Ninteisho
Started in Sept 1973 up May of 1982. Koshu Tokubetsu Kicho can be translated to mean "superior of the especially precious". This type of NBTHK origami is commonly called a "blue paper". It was the highest rank below Juyo throughout its use.
The Current Shinsa System
The current shinsa system began in September 1982 and is in use to this day. The ranking is shown below.
Hozon Kanteisho: Lowest level
1) Fittings up to the Edo period with correct mei, or mumei fittings on which the time period and school can be identified, and which are of a certain artistic quality may receive Hozon.
2) Fittings that meet the criteria given above can receive Hozon paper even if they show some wear or are slightly damaged, as long as those may be permissible in their appreciation.
3) Repair is permissible unless it significantly impairs the beauty of the fitting.
4) Fittings made in Meiji times and later which are of good quality and condition.
5) Cast fittings that are of high class and worthy being appreciated can receive Hozon if they do not date later than Edo.
6) Contemporary cast fittings will be rejected.
7) Works of iron that show a minor fire damage or a slightly damaged patina can receive Hozon if these damages do not significantly impair the aesthetic quality of the piece.
8} Fittings are put to "reservation" (horyu) if a decision could not easily be made on the authenticity of the mei. This also applies to mumei fittings in which an attribution is difficult to make.
9) Cast fittings made in Meiji times and later will be rejected.
10) Foreign made fittings cannot be submitted to Shinsa.
Tokubetsu Hozon Kanteisho: One level above Hozon Kanteisho
Fittings with Hozon papers can receive Tokubetsu Hozon if one of the following points is true:
1) Fittings with good workmanship and state of preservation.
2) Fittings with excellent workmanship and which are in terms of signature and/or workmanship valuable references.
3) Fittings of all periods by not famous artists can receive Tokubetsu Hozon if they can be regarded as among the very best works of the maker and if they are of a certain overall aesthetic quality.
4) Fittings which reflect a preservation of the craft, are extremely well made, and are of a certain overall aesthetic quality.
Fittings with Hozon papers cannot receive Tokubetsu Hozon if one of the following points is true:
1) Either zaimei or mumei fittings which show significant repair or remodelling.
2) If they are top grade kinko works but whose surface, motif areas or coloration is so much polished down that the characteristics of age can no longer be judged.
3) If they are of a good quality but the mei is no longer decipherable.
Juyo Token Shiteisho: One level above Tokubetsu Hozon Kanteisho and introduced in May 1958. Juyo means "important".
Fittings with Tokubetsu Hozon papersmay receive Juyo if one of the following points is true:
1. If of extremely high quality workmanship, of a very high artistic value, and judged as close to Juyo Bijutsuhin.
2. Fittings from all periods with fittings by not famous artists may receive Juyo if these fittings can be regarded as among the very best works of the maker and if they are of an extremely high artistic value.
Tokubetsu Juyo Token Shiteisho: The highest level and tarted in December 1971
Tokubetsu Juyo means "especially important".
Fittings with Juyo Tosogu papers may receive Tokubetsu Juyo if one of the following points is true:
1. Fittings of excellent quality and superior condition may receive Tokubetsu Juyo if their value is extremely high as art and reference work for our country.
2. Fittings may receive Tokubetsu Juyo if they are judged as the same as the top level Juyo Bijutsuhin or conceivable as equivalent value as Juyo Bunkazai.
Common matters for all categories of papers
1) If a kizu or other fault or weakness is discovered during Shinsa which is detrimental to the appreciation, an item may not pass.
2) Works of living artists cannot be submitted for Shinsa.
3) In the case items are submitted with older or lower papers and do not pass an initial or higher Shinsa respectively, they are returned with the remark "genjo" ("returned as submitted")
NBTHK Shinsa Standards – Published March of 2006 in the Token Bijutsu, he official publication of the NBTHK.
The original document consists of three parts. Token, toso and tosogu. The translation below is of the Sword section only.
1) Edo and earlier blades with correct mei, or mumei blades on which the time period, kuni and group can be identified, may receive Hozon paper.
2) Blades that meet the criteria given above can receive Hozon paper even if they are slightly tired or have kizu, as long as those may be permissible in their appreciation.
3) For Nambokucho and earlier zaimei blades by famous smiths, re-temper can be permissible if the blade is valuable as a reference, and if the jiha and nakago are sufficiently well preserved. However, this has to be documented in the paper.
4) Repair on jiha is permissible, unless it significantly impairs the beauty of the blade.
5) Blades made in Meiji and Taisho periods, and those by recently deceased smiths, can receive Hozon paper only when the blade is well made, zaimei and has a ubu-nakago.
6) Blades are put to "reservation" if a decision could not easily be made on the authenticity of the mei. This also applies to mumei blades in which an attribution is difficult to make.
7) Blades with hagiri may not receive Hozon paper.
Tokubetsu Hozon Token
1) Blades with Tokubetsu Kicho, Koshu Tokubetsu Kicho or Hozon papers with good workmanship and state of preservation can receive Tokubetsu Hozon paper, except for the following:
a. Either zaimei or mumei blades may not receive Tokubetsu Hozon paper if they are significantly tired, have kizu or repair which impairs beauty of the blade.
b. Re-tempered blades may not receive Tokubetsu Hozon paper unless they were made by famous smiths and their values are extremely high as a reference.
c. Edo period works by less famous smiths with mid or lower grade workmanship may not receive Tokubetsu Hozon paper.
d. Muromachi and Edo period mumei blades may not receive a Tokubetsu Hozon paper, as a rule. However, if a blade shows good workmanship, attributable to a famous smith, having ubu-nakago, and in good preservation, it may receive Tokubetsu Hozon paper.
e. Suriage cut-mei Edo blades may not receive Tokubetsu Hozon paper.
f. Blades with hagiri may not receive Tokubetsu Hozon paper.
* Among blades that received a Hozon paper in item 5 above, that may be considered the maker's best quality, these may receive a Tokubetsu Hozon paper.
1) Blades made in a period from Heian to Edo, having Tokubetsu Kicho, Koshu Tokubetsu Kicho, Hozon or Tokubetsu Hozon papers, of extremely high quality workmanship and state of preservation, and judged as close to Juyo Bijutsuhin, may receive Juyo Token paper.
2) Blades that meet the criteria given above and made in or before Nambokucho may receive Juyo Token paper even if they are mumei. Blades made in Muromachi and Edo periods, as a rule, have to be ubu and zaimei to receive Juyo Token paper.
Tokubetsu Juyo Token
Among Juyo Token, the ones of excellent quality and superior condition, judged as the same as the top level Juyo Bijutsuhin, or conceivable as equivalent value as Juyo Bunkazai, may receive Tokubetsu Juyo Token paper.