“R” mark under rear sight base?

[Mauserguy85]

Anybody familiar with this mark on the bottom of the rear sight base? Base is otherwise unmarked. What assembler/manufacturer would these be most often supplied to? I do not have any reference materials with me at the moment.

 

[Mauserguy85]

Nobody has a theory?

 

[bruce98k]

What rifle is it on..code/year?

 

[Mauserguy85]

Bruce, it’s on my CE42 “k” block. Never really noticed it before. It’s otherwise unmarked.