Found this on a local marketplace for just 15 Euros. It's a shortened Bismarck in different scales to match the length. Has a length of 55 mm and a height of 22 mm (so about 7/8th).

What surprised me is the grind: its a hollow ground but it goes from spine to thinner to a bit thicker again and then thinner again into the edge. I thought this was a Filarmonica thing, I didn't know it came on other razors as well. Does this grind have a name?

The gentleman I got it from showed me his collection of razors and stones when I came to pick it up. I held some JNATs in my hand, and the edge on this razor is also a JNAT edge.

I cleaned it up and used some alcohol on the edge. The wear pattern is good. I'll give the pin a tap later on, maybe polish the surface a bit with some compound.

I'm interested in Japanese kamisori. They are usually shorter than western razors.
So this will be a good experience to test a shorter blade.

I'll be trying it out tomorrow.

I think that's extra hollow ground?

Razor grinds aren't my forte, but I believe what you're describing is referred to as "bellied".

Ah yes that's right, thanks.