Similar to the Arsenal firearms, it will most likely require significant modification to the trigger housing and the firearm, professional installation is required.
Apparently not with the "protuberance". LOL.. aka "the rivet". It's a shame they don't have a real drop in for it, and when i call FA they couldn't give me a definitive answer about the fit in the Vepr. Considering all the best/high end aks have that tall rivet , you'd think FA would design around it, and give us a standard length safety selector too. For 500 bucks, id expect a better design. or more options than just the one trigger assembly. ;)
Not without altering the Vepr. I tried. Wasn't worth altering my Vepr to make this fit. Same thing with the Arsenal. There's a small round protuberance (I don't know what it's called or what it's for) just behind the opening for the trigger. It won't allow the Franklin Armory BFSIII to seat. It will have to be ground down to make it fit. My Vepr and Arsenal AK's are the only ones I have that have this part. Not sure how important it is or what happens if you grind it off.