Once again, Carlos unveils the mystery. Thanks! I never noticed the spot weld differences.
I forgot to add that some of my Romanian mags display a "22" stamp as well as the "0" stamp. One has them both on the spine; others only display one of the two; still others have no stamps at all.
For me, nothing is nicer for 7.62 than an East German mag. The quality of the metal work and blueing, as Carlos pointed out, is exemplary and stands out from the others.