This is great info, thanks. Had no idea that type M mags were 1951 mags--makes sense, I suppose. Are the Triple K 1951 mags any good? Also... "Triple K"? Are you kidding me? Seventy years and four generations... no one could think of a better name.
Anyway...
The gentleman from the Netherlands posted here a while back:
https://pistol-forum.com/showthread....locking-block)
If it's a gun I think I'll be shooting regularly, I would consider buying a few from him. Extractor springs are another consideration. Numrich apparently has those. though it does mention "fitting" may be necessary.
Also, just curious... what kind of a safety mod did you have in mind? Did not expect it to have a firing pin block. No surprise there.