Oh ok
Just call it wrist so I exactly know which part you mean ;-)

I didn't see any markings or stamps on the right hand side...

Perhaps I can find some signs of scrubbed down stamps in really bright light.

I remember a CSI method for scrubbed serial numbers on guns - they use some kind of acid ...
The metal is compressed underneath a stamp, even when scrubbed down it's visible....
But this would be a hell of a job and could ruin the finish of the rifle ....

Greeeetz
SM377Y