Thanks to all who suggested McMaster Carr (a new name to me and an
enormous stock of "everything") and to Ken Vinen on his experience
with flat leather belts.

My Western Electric rubber-tire drive wheel is considerably larger
than the Seeburg's, so the PPCo replacement is too small.  It appears
that the 3/8-inch diameter also means it has to be spliced.  McMaster
Carr recommends Super Glue as a low-cost splice.

Now I'm wondering if I should buy one slightly smaller and stretch
it over the wheel, or do these larger O-rings have "no stretch"
properties?  I'll call them today.

Many thanks,
Max Huff
Houston, Texas

 [ As I recall, Neoprene stretches very little but is very durable.
 [ Some urethane rubber materials stretch quite a bit and were used
 [ for phono turntable drive systems.  -- Robbie