Globe transmission with other motor(s)

[billbo911]

Forgive me if this has been addressed elsewhere. Searching did not seem to address my exact question(s). If this has been addressed, please point me in the right direction.

With the huge delay in getting P60 transmissions from Banebots, we are looking elsewhere for a rugged solution for transmissions to use on a roller claw.
There are a couple options already posted, but many of these alternatives seem to all have issues with reliability. Stripped gears seem to be the biggest culprit. Here is an example.

With that lead in, here is what we would like to do. We have several Globe motors from previous years. The motors may not be legal this year, but I believe the transmissions are. Additionally, the transmissions seem to be quite robust. If we can interface a 395/540/550 to the traansmission, I think we will have a nice solution.

Here is the issue we need to overcome: The pinion that is currently on the globe motor has an ID that is noticeably larger than the shaft on the three motors listed.

Option 1) Make a sleeve to go between the motor shaft and the pinion.
Option 2) Locate a pinion that will fit, or can be drilled to fit, the motor shaft and drive the transmission.

Has anyone successfully performed either of these options?
If not, what other options might we have to solve this problem?