I have a Polish copy that has the safety on the frame. First thing I had issues with was that the hammer would fall on its on about 75% of the time. After disassembly and reassembling the gun to include the fire control group about 50 times I found that the sear leaf spring seat had about half of it missing. At the time it took a little while to find parts, ended up finding a complete fire control group. Pulled the sear and leaf spring and it works flawlessly now. The original configuration like yours the half cocked position is the safety it locks the slide and and hammer. They are fun handguns to shoot, hot rounds! The only thing I'm not a fan of is the Iron sights are too small, but that is pretty typical of that era. PPU ammo was plentiful when I was shooting mine but really haven't looked in a while so I'm not sure on the availability anymore.
with the hammer in the half cocked position you wont be able to rack the slide and the hammer will not go forward until you move move the hammer to the fully cocked position. Now keep in mind that there isn't a firing pin block and that if you chamber a round and ride the hammer to the loaded chamber hammer down condition it may not be drop safe. I'm not sure how true this may be, I'm not one to test these things but have read a few posts about it and figured id let you know. Once I'm home I'll take a few pictures of mine and I think I still have the broken sear i can show you
