Ive looked at the stock a lot and it looks like the bulgarian/russian triangle folder is a pretty good match for the triangle part, if you crush the stock in a little bit to make that unique angle the type 88 has in the triangle
but the hinge is not like the type 56 chinese folder because it attaches to what looks like a fixed stock trunnion like a romanian side folder, but with that top button chinese locking type deal
i heard type 88s were in Panama back in the day, anyone have any data on countries that might have been issued some of these?