[rescue] SA4008 disk drive belt?

[Skeezics Boondoggle]

Would anyone just happen to have a replacement Shugart SA4008 disk
drive belt (part #10904) laying about?  Or suggestions for how to
safely refurbish one?

It's physically in good shape, with no apparent cracks, warping or
damage, but it slips off just a few seconds after applying power.  The
inside of the belt has pretty much worn smooth.  There are no
instructions in the OEM manual or readily apparent tensioning
adjustments on the drive.

Thanks,

-- Chris