Probably well made White Steel #2. Fairly easy to sharpen, but the edge is quite tough. These are over 30 years old stock, so the age hardening effect might have hardened it to this level.

Since they are so old, there must have been abundance of good quality red oaks back then, such a dark colour red oak is used for even the economy tools. Recent models, even from renowned makers such as Oouchi, Yamahiro, etc. are forced to use lighter colour red oak. Sometimes even if it looks quite dark it is because of the red stain the handle makers applied to make it look better.... With those, once you apply paint stipper to take off the protective laquer, or simply sand the handle, the stain comes off leaving you with light pinkish colour.

Although these a very old, there is basically no rust at all. The back seems quite flat, and it has been shapened fairly well by machine, so it should be easy to make it properly sharp from here.

The lamination has been done superbly well. The steel is thin, and both corners are wrapped very neatly. I don't know why this can be possible for such an affordable price. Also one thing I notice is that the lamination line looks strikingly like Kikuhiromaru chisels'.