The last time this came up I looked around -- pattern makers use it, so it's available mail-order from pattern makers supply houses.  Unfortunately, it's available in lots that are sensibly sized for a busy pattern making shop, not modelers.

Someone needs to get one lot and then offer them for sale in onsie-twosies.

Norm,
Your second link works and Estelle Semmes is the owner and still does have plenty of various size leather fillets. Thanks for the link, in order to send Estelle an email for pricing you will need to reply to the signup page, worked fine no other stuff added to my computer when doing it.

Best,    DennisT