I bought a VEPR 12 years ago with the welded folding stock. I'm wondering about replacing it. The state I live in does not allow a folding stock on a shotgun so it's only legal with it welded open. I'm wondering about replacing it with a fixed stock or a M4 Buffer tube since collapsible stock is legal.

I was told in my case the whole rear trunnion needs to be removed and replaced for it to accept AK stocks or to add an M4 buffer tube. It looks like the non folding stocks with the pins are the only kind that can be replaced by drilling the pins. There maybe a m4 adapter for mine but then it would involve unwelding the folder thus making my shotgun illegal and they are folding adapters.

So weld the new adapter in place, if that's what your state requires, after it's installed.

(Most every time somebody pins & welds an AK muzzle device, there's a brief moment where it's a SBR until the weld is done, but that's how it goes.)

If you'd rather start with the later fixed trunion variant, the earlier gun you have (welded folder) is much more desirable, so I'm sure someone would trade you (+cash) for a later import.

The benefit of modifying your current gun would be (if you ever move to a free state) you could just slice the spot weld, and have it fold again.