Ray Singer

Yoshimasa.

What I believe is being said is a nickname indicating the respect that the smith had, such as Kiyomaro being called "Yotsuya Masamune" and Shinkai referred to as "Osaka Masamune". Frankly, I've never heard the nickname "Musashi Masamune" attached to anything other than the name of a famous blade by Soshu Masamune, so I am not sure where Robert's reference comes from.

I tend to encounter a number of tanto with shingane present. I was actually just handling this one a few ago, which is a wonderful piece for the intact Nanbokucho date (and also special for having been in the collection of our friend Arnold Frenzel). But as shown in the photos about 60%+ of the ji displays shingane. The Shitahara Masamune is about the same. http://www.nihontocraft.com/Bizen_Yukimitsu_Tanto.htm

I don't think there is a mystery to be solved, the description of the tanto that was written down on the page is accurate. It is tired in places, the jitetsu is worn and there is shingane showing. The seller is honest and I am sure he will send additional detail photos if requested.

Sayagaki reads Musashi no kuni ju Shitahara Masamune saku. Kanteisho reads Masamune (Shitahara)

It is a zaimei Shitahara Masamune. I know the sword well, it is owned here I Miami. The description is accurate, indicating that the blade is Shitahara Masamune (not the famous mainline early Soshu Masamune).

Takada ju Yukihisa

Mark, I would look at 貞弘 as one possibility for the mei. I think that the mune has been lowered and the length reduced, rather than this specific uchizori, nagasa & sugata being original to the blade. Regards, Ray

This is a wonderful, flawless, ubu shodai Harima Daijo Tadakuni wakizashi. It measures 1 shaku 8 sun or 54.5cm. The hamon is a notare composed of small gonome with ashi. The jihada is a perfect konuka-hada with no hint of tiredness. In excellent polish with silver habaki and old shirasaya. The blade has Tokubetsu Hozon kanteisho. $5,950 (plus shipping and PayPal)

Another example here.

Sato Yukihira saku.

I see that they have neglected to remove the Ebay listing, and translated as Matsutsukido Tomozen. https://www.ebay.com/itm/274595426770

I believe the correct full reading is Matsugetsudo Tomoyoshi + Kao

Ushoshin. http://swordsofjapan.com/project/ushoshin-katana/