I just remembered, not only did they come with my parts kits, sometimes I got two. My CTD Romanian underfolder had two "sets" of the extra FA trigger control group parts. Their serial numbers weren't too far apart, either IIRC. A Romy "G" kit also had two in it. Forget which vendor that one came from.
But even more weird to me, my M64 from Apex came with a Romanian disconnector loose in the packing paper and not in the bag of Yugo parts - which was missing the disconnector.