Thanks.
I checked several places, and no one had the 21 tooth, but I found a 20 tooth at Antique Auto Supply. I eally wanted to find the proper combination of drive and driven gears to get a good speedometer reading, but no one that I called had what I am looking for. But at least the 20 tooth will give me a working speedometer.

I just wish I had found the loose bolts before the gear stripped.