Hi OZ,
possibly from Ingersoll Rand air starter from 6 1/4" Bore Vee engines.
cheers,
Eddie B.
Well, I recognize it as a friction-clutch type inertia Bendix drive.....but I don't know the application.
The fact that it is a straight tooth drive indicates to me that it is not of the pony start Caterpillar era and by the time Cat used straight tooth drives the inertia drive was history.
I do show that style drive being mounted to the Delco-Remy early 40MT type starter but without a starter number I have no way to identify the application.
I'll look some more.