First of all, thanks to all who responded to my SOS.
The problem was a nominal 1 inch shaft and nominal 1 inch bearings. The
shaft was a hair oversized and the bearings were a tad under.
Resolution: Buddy with a coarse grinder shaved the shaft for me to fit
the bearings. Tried a couple of machine shops first, but no one wanted
to touch the job as the discs for the drum already were attached.

Bottom line: I now have a pretty nice drum sander at a small fraction of
the commercial products.

Larry