Re: Md. 70
First I'm no gunsmith, but I have built some dern nice target Model 70s, I think they are easy to work on.
As for push feed vs. control feed, it's preferrance. I was concerned with the little extractors when they came out. Even bought a spare and put in in a hole I drilled in the stock under the butt pad on my Post '64 375 H&H. That was in 1974, it't still there. Never broke one. The model 70 is my favorite action.
But, I see no problems with the post '64s. I personnally think the new FN Model 70 is the best of the lot.
One time I met a guy who traveled the native Villages in Alaska buying up rusted guns, (eskimos are not known for taking care of equipment). I bought "6" Model 70 actions from him ($250 total for the lot). Four I made into 1000 yard guns in 300 WM. for the AK NG Rifle Team, (mine included), One I made into a 243 hunting rifle for my wife, and the last I made into a Vietnam Era Sniper Clone.
They are great actions, I see no reason to get hung up on push feed vs. control feed. Both can be turned into great rifles.
Below: Post '64 Model 70, 29 inch Douglas Prem. Barrel, 1-10, 300 WM, Bishop Stock. Redfield Oly Sights also set up to take my Weaver T-10.