Rare U.S. Resident Evil 3 PS1 Uncensored Flying Heads Gameplay

I'm a collector and I saw A LOT of pc/console games (russian bootlegs). They are often chinese or korean games unofficially translated to russian (sometimes even dubbed!). Official playstation thai, chinese and japanese releases were (partly) uncensored, you can detach zombie heads with a kick. So most probably the source of your russian bootleg was a copy from one of these countries

You don't have to be surprised about someone modifying it 17 years ago, they did this sort of things even in the space invaders/pacman era.