TKB-263 (ТКБ-263) prototype pistol by Sergej Alexandrovich Korovin (Сергей Александрович Коровин, 1884–1946), made in 1928, chambered in 7.63 Mauser (7.62 mm Tokarev not having been introduced yet). http://forum.guns.ru/forummessage/15/547755.html
Currently working on my next cosplay project: Kyle Katarn from the Star Wars Dark Forces/Jedi Knight saga, i.e. the guy who actually stole the Death Star plans and then became a jedi knight. Here's the first finished prop I made for this outfit, the Bryar pistol. This is actually a Star Wars Rey's Nerf blaster I modified according to the Bryar pistol you see in the videogame's cutscenes, but it still works as a normal Nerf.