I've built a half dozen of these and have several points to note (some are repeats from above posts):
First, building these in stock configuration doesn't require compliance parts, since they are legal to import. However, despite not being a FA rifle, the OE receiver does have the infamous "third hole" for the "safety sear". My personal opinion is that the whole FCG should be replaced for legal reasons. Tapco G2 or RSA FCG's drop right in. . . . better safe than sorry.
Second, building a PSL with a standard AK stock and pistol grip is likely to trigger 922(r) and the need for compliance parts . . . at least that's MHO. The availability of compliance parts might be an issue: 16 - 6 = 10, where the six compliance parts would be: Receiver, FCG (3), US-made buttstock, and PG. Alternatively, one could substitute a custom made gas piston or muzzle brake for the buttstock. Note that there is a fair amount of debate around this issue, so YMMV.
Third, as far as I can tell all the recent PSL's sold have have pin-on or welded breaks. So for the 922(r) reasons cited above, it would be prudent to solder or weld the muzzle break if you're not intending to add the full set of compliance parts.
Fourth, the PSL has a ring of metal at the breech. On the Mauser M48 the ring is called a "safety breach". I'm not sure what it's called on the PSL. In any event, it's fragile . . . pushing the barrel using only pennies or copper washers could damage it. I made up a special brass cylinder so I could push the barrel without touching the ring.