Need some opinions/ advice from some of you "gun hands"

There's a LOT of stuff to digest here!! On a side note, my eyes don't focus on iron sights anymore, and can not really be corrected with glasses. My neighbor gave me an old 4X Weaver and I bought a mount and rings and got it hangin onto the 30-30. My old Daisy powerline .177 now has a little scope, and the fire (turns out to be minor) damaged 10-22 has a Picatinny rail waiting when I get it cleaned up

The Stevens 84C (bolt, mag fed .22) is a different problem. It has two small holes about an inch apart right near the rear of the receiver, approx 45* off level. I have not ID'd yet, what they were for. They do not fit the Weaver mount claimed to fit, which I have.