Heresy! Sacrilege!
We've all had those thoughts when we get frustrated with Rajkot quality issues. It's the only semi-affordable low speed engine in production, however, for those of us who really value that for auditory reasons.
The balance issue is easy to solve; if you've got plenty of movement on your mounts you could go straight to Mr X's wheel chaulking method.
If you've experimented some without good results, that's likely because your two flywheels are badly mismatched. 38ac's brilliantly simple method of getting the counterbalances centered relative to the keyway and matching the two flywheels will quickly remove all the confusion, and saves a lot of time. Then if it still moves up and down, add equally to both counterbalance sides of the flywheel, or opposite if it's moving fore and aft, 2 oz per wheel increments is a good starting point.