Long Barrel Madness + Questions

[worldoftone]

Long story short . . . bought a $750 shooter, parts Luger under the assumption that it worked fine. Well, hasn't worked correctly since I bought it. 16-inch barrel looks like. HAD scope, forearm etc. before today.

Problem #1: Original breech block failed. Got breech block from GT. Gunsmith at store I bought it from couldn't fix it.

Problem #2: He couldn't repair it mainly for firing-pin issues where the pin wouldn't strike the primer hard enough. Took it to second gunsmith. He fixed firing pin. Firing pin broke after a couple of rounds at range. He repaired the pin. Took to range today. Pin broke again eventually (not surprised) but here is what I DID find out before the pin broke:

Problem #3: Pistol would not extract round or cycle correctly. I then wondered if weight of scope etc. attached to barrel would have caused the function issues. I removed forearm, and scope. Pistol started firing correctly, but had some intermittent extraction issues. Then the scope mount blew off (not surprisingly - see pics). After that, the pistol started working much better, but then the firing pin broke again.

Soooo . . .

Question 1: Pistol does not have a rear sight. I looked at the way it is refinished etc and I THINK I might need a new toggle. Please see pics. If so, I'll have to get one from someone on here. Unless there is a way to affix one back on this toggle - I kind of doubt it. I am planning on leaving that abomination of a scope off the gun. Any other rear-sight ideas for me?

Question #2: Please look at the machining marks on the barrel that were used to mount the scope. They bored slightly into the top of the barrel before affixing the scope rail with epoxy Will this affect the safety of the firearm?

Question #3: Can anyone tell by looking exactly WHAT type of barrel this is? Numrich, etc. No stamps or marks on the barrel whatsoever.

Question #4: SN on the frame is 86515. Looks to have been slightly machined off before it was blued. Where exactly does that put this frame date wise? Receiver is a 1939.

I have read threads on here about these long barrels and understand that they are a bit tricky to get right. I've already lost my butt on this one, so I think just getting it operational would be nice!

- WOT