B&S 5 hp pull clutch replacement oddity

 My Merry Tiller has a 5 HP B&S engine with a bad pull start clutch.
Every dealer and parts supplier I've contacted or ordered through has
sourced the pull clutch with the threadded shaft mount. The one on my
Merry Tiller however is a hex mount, press fit,  with no threads on
the shaft. Does anyone know how I can get one of these?
The Serial/Model number  search have been no help in my search , in
fact they point towards an electric start ring gear assembly.

The local parts dealer say rebuild the one I've got, but it needs the
bearings for that. ANyone know what size?

Ideally, I would like to replace the unit.

Thanks

 MrMoto wrote:

What holds the flywheel on? Is it just a nut or is it a nut cast inside
an aluminum housing about 3" big?

--
Art