His advice doesn't make sense. "Oversize rings" includes boring the cylinders and fitting oversized pistons to match the rings. Does it make sense that an engine 60 years old wouldn't need attention to the valves, cam, lifters, rocker arms, etc.? While it might be possible to do a minor rebuild like we did back in the 50's and 60's, times have changed. Doing things like machining the connecting rods for insert bearings should be part of a complete rebuild- - - -reground crankshaft, possibly new cam & lifters, valve job, etc. Trying to do a vast project with half-vast methods doesn't sound like a good idea!
Jerry