
I purchased a plastic Losi spur gear for the steel insert it comes with, and used the (modified) steel insert as a diff backplate.

The adapter plate to bolt the pulley to the diff.

All assembled minus the internals, and also filled with epoxy to act as a bushing between the pulley and diff cup. There is grease between the diff cup and epoxy so that the epoxy bushing/pulley can slide off the diff cup for easy maintenance.
There's much more progress to report, but that's enough for now

However, I will say that a shipment of belts and pulleys arrived today