The 9x18 Makarov is a more powerful cartridge than the .380. That PA-63 is a pretty good gun, though like most FEG pistols, it needs going over by someone to smooth things up (including grinding down that Johnson and Johnson* trigger). Once done, it is a pretty good gun and they seem reliable and reasonably accurate. In spite of the outer resemblance, no parts interchange with the Walther PP.
*J&J makes Bandaids and the PA-63 trigger increases their sales.
Jim