Several gear profiles were ordered, and tested to see the advantages/disadvantages of the various configurations.

Here are some of the prototype parts.
The gears mesh quite nicely, and run quietly up to about 1500 rpm.
As soon as the counter that's on order is received, I can give it a proper road test. Final production can probably begin in a few weeks.
Tom has a local supplier who can make one-off prototype parts. As the initial tooling cost is likely to be high, Tom has elected to make full-scale mockups, and test them, before contracting to buy the fabricated gears in quantity. Measure twice, cut once.