FWIW my PSP mags read either
P7
9x19
1A
or
P7
9x19
1F
FYI the bottom 2 markings are both letters and are in fact manufacture date codes "IA" = 1980 "IF" =1985, "IH" =1987
The two psp mags I have lying around are same as above with IA codes, no other markings.



























