Alvin,
The stamps appear to be Chinese, and I assume that they are either acceptance stamps or property stamps (or maybe they say "Read the manual before using the gun"
)
I don't have a picture of the backstrap, but it does have a stock slot. There's also quite a bit of pitting under and around the grips, seems like they have been wet for a long time. I can take a picture if there's anything in particular you want to see.
The lanyard ring is made like a heavy duty key ring, so it would be interesting to know if this is original.