What difference is it going to make either way? Are you going to rebuild it just because of one check? Get some miles on it before deciding. Drive it some to loosen it up and get heat into it, then check the compression, but in the long run, as long as they are even across all six, it will run just fine. Its going to be a rare find that all six are low and still be even with each other. One or two low is a problem, all six is a gauge or test problem.
The correct way to test is have the engine warm but not hot, all six plugs out, carb wired open, fresh battery with strong cables, and four to six rotations per cylinder test. This should be a running engine with oiled cylinders, if its not, oil all six cylinders and crank the engine to coat each one top to bottom. You want each cylinder test to be identical in time and conditions.
Joe
