The problems never end

[Bob Culver]

Have heard many tales of cars of various makes run with damaged cylinders. The ring gap can be .030 forming a leakage path say .030x .010" so engines tolerate considerable leakage. Some claim scores can be filled with solder!
Old cars which have been extensively worked on by all and sundry over the decades are usually riddled with troubles, and Sevens were worked on far more than most. It often takes much more than an experienced modern general mechahic to sort. A major reason moderns are so reliable is mechanics have no cause to work on them.