My 1974 P64 was purchased when they were fairly new on the surplus market, for $139. At the time, there was a lot of grumbling about the "Polish Makarov" from the Makarov fans...nobody wanted them.
Mine looked like new.
Yes, the DA pull was unusable. I did the mainspring switch, which worked great. I also noticed that the trigger bar pushes outward when the trigger is pulled. I gave it and the inside of the slide where the trigger bar slides a light polish, and I keep some CLP there.
I also put in a heavier recoil spring.
It shoots much better for me now.
The recoil is pretty sharp, but the heavier recoil spring helps that. I am not afraid of recoil...a Model 19 2.5" with the small wood magna grips and full power magnum loads is what I call fun. But the finger rest on the P64 smack my pinky hard.
Still, it is very accurate.
Look for the simple Polish issue shoulder holster. It is very lightly constructed and looks cheap. However, this winter, I found it carried the P64 very well. Under a fleece top, it was zero burden to carry, easy to access, and unnoticeable. Best part is they are cheap.