bearstalker: Might have answered before you asked.Back when the M70 was designed (1937),scopes were a sometimes thing,and many used receiver sights.Those taps on the side were there for that purpose, to mount Lyman 48's and 57's.Years past I have done much target shooting and hunting here in New England with Lyman 48's and 57's on pre 64's.
The rifles came "set up" for iron sights.
And "yes",some scope mounts used those holes on the side.....can't recall the names though.
Some folks today say the matte finish of the pre 64 receivers is an indication of "poor quality finish",giving the rifle a two tone effect....this makes me smile as they demonstrate ignorance.
Fact is,riflemen used ironsights back then,as well as scopes later on.The matte finish, and the wavy lines on top of pre 64 receivers,as well as stippling on the front sight ramp,were there to prevent or cut glare from stray sunlight for those using iron sights.
This stuff is lost on many of todays riflemen who have never used irons for any serious target work or hunting.There was nothing on a pre 64 that did not have a useful "purpose",given the times in which they were created.
