12r

Hi all! I am a new owner of an old Marlin 81DL. It has the 12R peep sight and I have some questions about the sight which I hope to get help with. From postings here and at RimfireCentral I believe the gun is 1941-1950 vintage. 5-rifle grooves (Ballard) model stamp reads 81DL -------- A; no...