I had my 49 Kaiser engine rebuilt by a fellow 1/4 mile away that has rebuilt many a Massey tractor Continental, and many other engines. Entire parts (including new pistons of the right oversize, valves etc) for a Continental were almost entirely on the shelf ready at a small parts place 7 miles away in a small village. Massey-Fergusons were very popular here! I wish I could get into the business of subcontracting engine work through him, because it wasn't an expensive job at all, compared to what some of you seem to have paid.
It went from an engine that used 1 quart of oil per hour of highway driving, MOSTLY to blowby, and not smoking very much, to a very tight and clean engine.