Josh Plemmons

So I have a 92 W250 cummins that the odometer/ trip meter quit working on the speedo. Did the typical gear swap. Which it did have a bad gear. Put it together, made sure the gears meshed and operated correctly. Once back in the truck, No luck.
Also when I went to take out the gears on the speedo the entire motor and gears came out as one. Practically fell out of the stepper motor housing. Which that could be my problem too? Bad stepper motor?

Anyways after messing with it several times I can’t get this factory gauge to work. Tried a few salvage yards and found a 90 B150 with a good speedo in it. Speedo is identical (seems like?) minus the assembly and connections points.
Am I able to swap those speedo internals onto my first gen speedo housing/connection points? And would it operate correctly with the 1st gen cluster mother board?
At this point I don’t mind trying to mess with both speedos since I presume mine may be done for anyways. Just don’t want to ruin the mother bard that the entire cluster plugs into.
Any help would be great. Thanks