I heard a lot of feedback about match balancing. Since I was putting new seals, rings and bearings in my 300D motor, I decided to bring everything that could be unbalanced to be zero (neutral) balanced

Crank, flywheel, harmonic balancer, front crank pulley were brought to a machine shop where they were cleaned, measured for tolerances, and balanced (only the crank itself ended up being neutral balanced, everything else needed balancing).

It seems that the flywheel and front crank components may have been oddly (not neutral) balanced (but the crank itself was neutral balanced) - has anyone else found this to be the case on other 300Ds?

above: balanced / cleaned components - note the shiny new drill holes on the 240D manual flywheel, harmonic balancer and front crank pulley.

All you needed to balance was the flywheel.