My parts book for 1929- 50 doesn't list the ring gear separate from the flywheel. Number of teeth not listed.
You can take the cover off an mark a tooth and then rotate the engine (have buddy or missus
turn the crank slowly whilst you do the counting. There is no way to go about this chore of counting the teeth without the collection oil all over your clothes so take your clothes off before crawling under there. It's harder to get oil off your skin than it wash it out of your clothes. Is too! (If you're married then much less nagging directed at you.)
Group no. 0.666 and part no. 837243.
As the flywheel and its gear are already balanced, I would think the vibration is coming from somewhere else.
I doubt adding weights to the flywheel is a likely fix for any otherwise cause for vibration. Nonetheless, if doing so results in less engine vibration then such fix will only be masking the real problem.
I agree with Tony (down under one). Also, I admit that I don't know what to tell you other than check the harmonic balancer and I have no expectation that that could be the culprit.
Maybe change spark plugs. Most times they fire but sometimes they don't. Sort of like a cat obeying you. They don't: unless to do so is within their own best interest at the time. Think some miffed missusses
:too. Agrin: (That missusses is more difficult to say and spell than hippopotamuses. Is too!)