Jeff - Sorry if my reply mislead you. I don't actually have any of these.
I was just offering the information to see if it can help you find what you need.
Perhaps a fellow 'Bolter has something stashed away or sitting on a shelf somewhere that will replace your missing one?
Since you've indicated it's for a 1/2 ton, can you look inside the speedometer plug port and count the teeth on the speedometer drive gear that is pressed on to the front U-joint yoke (if still installed)? It should have either 4 or 5 teeth and that will tell us what driven gear tooth count you need.
On a further side note after rechecking the 1946 Chevy Car/Truck Shop Manual, the GM# 605061 gear set used in the 4.11 rear gear ratio 1/2 ton trucks is the exact same set as used on the 1941-48 Chevy passenger car 3 speed when the car was equipped with the standard 4.11 ratio rear end.
If you can find a 1941-48 Chevy car 3 speed, you may be able to snag the gear from one of those.
Finding a donor car 3 speed is much more likely than finding the truck top shifter 3 speed.
Best of luck in your search!
