Tim Rickman wrote:

> The round belting material he used has turned hard and brittle,
> and I need to replace this material on two roll frames.

I have seen such round rubber belting for sale in ("gasp!" goes the MMD
congregation) an automotive parts store.  It is sold as an "emergency
fan belt".  It's a long rubber tube, with an internal connector just as
you described, designed to be cut to fit whatever fan belt you've
broken.  Perhaps you can take a look at this product and see if it fits
your needs.

Rick Inzero
Rochester, NY