Ah... the mysterious PS prefix. usually these are not dated if you look at the serial charts, however some are.
In most of the ones I've seen photos of, they are what would I take to be the original stamps, given the oddity of this prefix, they may have used a different stamp method....... or.... maybe
like China, Russia sent Romania a train car full of bits and pieces to study and copy(like the SovietSino), and these were built and PS stamped, while the later native model followed normal Romanian prefixes. (Purely speculation there
, I've not held one long enough to dig into the guts of it, BUT....we needs one, we wants one
Romania really had no known reason to grind them down and reserial units for super secret incognito missions, besides, they still have the Cugir stamp from what I've seen as well.. Even for refurb purposes, the history of the rifles show, they were not overly concerned with serial matching this and that.... they wanted a functioning good working rifle. Romania was a broke arse little nation, function was chosen over form and fluff, and I'm sure matching numbers don't really impress soldiers come go time, rifles that work, do.
If it is a Russian sent parts kit to Romania....maybe the PS prefix is a jab back at Russia.. PS = Piece-o-S*it
I'm sorry.. but, it is kinda funny...