We seem to be getting into a mass of confusion with Haruta Ietsugu being dragged into the picture based on the supposed shape, the use of the kanji Ie.. and something to do with the koshimaki (?) I think at this point it is worth summarising what we really know.
1. We have an eight plate helmet of goshozan shape whose external appearance and apparent number of plates has been modified using lacquer at a later date.
Attributions based on the present shape make the assumption that the lacquerer, whilst adding suji, has preserved the essential shape of the original.
2. The helmet is tameshi with five bullet dents internally at the front, sides and back.
3 The helmet bears the signature: 大和 (no) 守 藤原 家義 Yamato (no) kami Fujiwara Ieyoshi.
The kanji Ie 家 was rarely used by the Haruta. Sasama in 'Shin Katchushi Meikan' lists only 3 out of 42 Haruta armourers using that kanji. One, an Iehisa never signed Haruta
but was claimed by them, Another Iehisa only made tsuba and for whom no armour parts are known and thirdly an Ietsugu who worked in Harima and later Bizen who
changed his name to Hayata and stopped making armour and began to make tsuba. It is accepted that Sasama's work is far from comprehensive - armourers, because
the handled skins and leather were regarded as being of very low social status and hence not recorded in the same detail as swordsmiths, but it is the best source we
have at the moment.
In the same source, i.e. Shin Katchushi Meikan, Sasama does list a Fujiwara Ieyoshi 藤原家義, the same signature as in the helmet, whose real name was Shimizu
(or Kiyomizu) Chubei 清水忠左衛 who lived in the mid Edo period who made a surviving helmet with Iga no kami Kinmichi. It is not known whether Shimizu Chubei was a
professional armourer or not.
4. Iga no kami Kinmichi was the swordsmith tasked with allocating honorary titles to other smiths. Honorary titles awarded to armourers are uncommon although other
examples do exist.
The armourer who made this helmet has the title Yamato (no) kami ..
5. Haruta armourers tended to use a concave peak on their suji kabuto
This helmet does not have a concave peak but one that is flat in section held in place by soft metal rivets.
Summarising: We have an eight plate tameshi helmet, modified by later lacquering to look like a 62 suji bachi of goshozan form. It is signed by a Fujiwara Ieyoshi with the honorary title of Yamato no kami. Notice that there is no mention of Haruta. There is no recorded Haruta Ieyoshi using these kanji, and Ie, is a kanji that was very rarely used by the Haruta. However, there is a known helmet maker who signed Fujiwara Ieyoshi using the same kanji who worked with the swordsmith Kinmichi who was responsible for awarding honorary titles.
All my careful editing has gone to pot - like me.