Sears Roebuck Model 53
My 30th edition Fjestad confirms that the Sears Roebuck model 53 is indeed a Winchester model 70. It most likely has a 1" X 16 TPI tenon and if it is a push feed model, the breech is flat with no cone and just a slight chamfer to accommodate feeding.
I would expect a model 70 barrel to fit, but it will need to be from the same range ( pre 64, post 64). As with most barrel swaps on factory hunting rifles, the sights and markings usually do not index correctly so the barrel needs to have the tenon shoulder adjusted to get the barrel clocked and then the breech needs to be faced off the same amount and the headspace adjusted.
Scott Roeder