Definitely not Chinese as they are 2 rib and flatblack. Followers can certainly end up anywhere. Most unmarked mags are Romanian, but I don't think they have that many welds. I'll defer to the spot weld experts who will be along shortly.
They could potentially be Sino-Soviet magazines. Those have the appearance of Eastern European magazines but they were made in China with the Chinese follower style. Sino-Soviet magazines have “66” in a triangle on the back side of the magazine.
I have several of these too. They all show evidence of refurbishment (rust marks under the finish etc.). That might explain the late follower. It just got mixed up. They were sold by zib Militaria in boxes with 99% chinese mags and some north koreans. Only way to be 100% sure is a 66 in triangle stamp (chinese) or a star in a circle (north korea). If they miss it i would guess chinese, because they are more common.
I think we had a similar batch get imported maybe 8ish years ago. I remember buying a ton of magazines from Aim Surplus. They were mostly Chinese style magazines but they also had Sino-Soviet and North Korean magazines mixed in.