Craigster, I suspect that the lads I'm remembering were either RF/PFs or some warlord's militia--Binh Xuyen or Cao Dai early '60s. They may have been armed by the French originally; the French had LOTS of WWI US arms that they were given by us in WWII. Yeah, the "real" ARVN originally had lots of M1 Garands and M2(not so many M1) carbines. My brother was an advisor to one of their armored cav battalions early in the war and "borrowed" an M2, which he actually thought was an OK weapon.
Many of the "allied" European armies that were formed by us in England and North Africa (Free French, Greeks, etc.)were equipped partly with 1917s. Not to mention about 3 zillion Chinese.