Model A Engine Noise and worn timing gear

[jguedel]

Hello

I am a new Model A owner having bought a 29 Tudor at the Hershey RM Auction. This engine has a knocking noise. We pulled the oil pan to discover that all rod bearings appear tight but the timing gear is missing many teeth. The engine ran fine, starts fine, seems to have enough power. The knock comes and go's at different rpm. Would the timing gear cause this noise? would a bad main bearing cause the timing gear to chip and be causing the noise?
Thanks for any help.
John