I have one that was already d/t'd when I purchased it. The receiver drill holes are 22mm from center to center. The front sight drill holes are 14mm from center to center. From the back drill hole on the receiver to the front drill hole(closest to front sight) it is 8 7/8". From the top of receiver to top of bbl on the bbl holes, it is 3.5mm. See pics as well. The back base would be about 3.8 mm thick and the back base 7.3 mm thick. The receiver base would take the same base as a current Savage 110 front base. It would need a long scope, probably in 7/8" tube. How far off am I and any ideas on which bases it takes? Thanks in advance.

I'd first call Brownells and talk to a tech.
That failing, I'd find a friendly gunshop with a large stock of Weaver bases and start trying various ones. Level the bore first and try bases till you get two that will also be level.

Given the rifle's vintage I think it may have had a target type scope on blocks (Lyman or Winchester) as even a Lyman Alaskan has a maximum mounting length of about 8.5"

Now, since it not really a collectors item, the easy way out might be just to get a one piece Weaver base that fits and punch more holes in the receiver top,