if the engine had 145+ compression it's real unlikely it hasn't been rebuilt in 53 years ... the road draft smoke is blow by, rings worn .... black plugs [sooty black] mean running rich, with blow by, that could be why the oil is dirty quickly .... if the engine has sat for a long time the valve seals are likely shot and the guides may be worn, but that would cause exhaust smoke on first starting, and oily black plugs
Bill
