Side plate marking
 

Any idea what a S 80 marked side plate came off of.
There are no other marks that I can see.
Thanks in advance.

yofo, the "S" next to the serial on your side plate, would indicates to me that it was originally used on a Mauser K date (1934). Depending on the style font of the (S or scriptic German) would determine, if it was early or late K date. Tom