I am looking for a supply of a small quantity (say, 5 metres/yards of
both sizes) of round cross-section belting suitable for making endless
drive belts.  I have tried neoprene and butyl rubber used for 'O' rings
but it tends to be inelastic and too smooth.

The belt material must be capable of making a strong joint either by
suitable glue or easily applied heat weld.

The actual diameter is not critical. The smaller one may be about 1/8"
diameter [3.2 mm] and the larger 3/16" [4.7 mm] or metric equivalent.

The belts are needed for a custom-built musical automata which uses
belt and pulley drives.

Many thanks if you can help.

Paul Bellamy