Typical CGT odometer repair no good- any thoughts?

[only5kgt@uswest.net]

Hello audifans:
I acquired my '85 CGT with a dead odometer... bad practice,
I know, but the overall condition of the car suggested its
123,199 indicated miles weren't far from the truth, and they
were gentle ones at that. Experience gained in a trip to Las
Vegas-L.A.-San Diego and back to Tucson, as well as six
weeks of daily running (no faults of consequence yet)
so I wasn't too worried. But, upon trying to rectify the
last remaining flaw (fixed the CC and rear wheel bearings,
even) I stumbled twice. I thought there was a white worm
gear which comes out of alignment with the flat gear
alongside. Sure enough- the two didn't mesh. I meshed them
and tried to glue it, on two different tries. JB weld the
second try. Not so much as 1/10th of a mile has registered.
Did I have the theory wrong entirely? What's the alternate
way to fail? The speed reading works fine.
TIA,
Rob
'85 Coupe GT 123k forever...