George what are you wanting to build? I have one that has never been back to the factory for the ejector fix. Never been fired, but that is not to say it is like new either! lol I used it as a fit gun for stocks. I am sure it will clean up.
Are you wanting to make a bench/varmit rifle, or something more akin to a field rifle?
Those .22 mags can be fussy in an auto. There are a lot of different power levels and bullet weights available. Since rimfires operate on the "blowback" principle, some ammo is very hard on the guns and some ammo won't even open the action. We did a lot of testing for accuracy with a 77/22, and then had Volquartsen build a 10/22 custom heavy-barrel rig for just that exact brand and type of ammo. Volquartsen carefully adjusted the action and springs to operate and feed that exact ammo, and it was a fantastic prairie-dog gun out to 200 yards. We got 1/4-3/8 groups at 50 yards, about an inch at 100, and about golf-ball size at 200 yards pretty consistantly. ....Rick