The first part appears to be a firing pin protrusion gauge for a P.08 Luger pistol.
The second part is (I believe) a sear for a K98k rifle. It looks like it was made at either Radom, Poland or Steyr, Austria, depending on where WaA inspector/team #77 was at that point. Judging by the roughness of the finish, I'd guess late war Steyr.
I'm not familiar with the third part.
The last part looks to have a Tula arsenal marking (triangle marking at the top), possibly from a mosin or SVT.
Almost looks like an SVT-40 sear when I compare it to mine.
Izhevsk is what I think you mean......and even then I don't think it is an SVT part ?
Tokarev SVT-40. Identifying, collecting and FAQ.
The BK in box mark looks like a YUgo mark I've seen but it was on a M57 (and this isn't for that!), but no ideas beyond that.
Sorry, yes izhevsk. I was thinking of my SVT which is Tula, but I do think its similar but I could be wrong just a guess but I'm sticking with it being a Russian sear of some sort.