6x4.5 Card Slide Mounts

[whif]

Does anyone know of a supplier of 6x4.5 self adhesive card slide mounts anywhere in the world. Adorama and B&H in NY both stopped supplying a couple of years ago. Now Process Supplies in London, who sold a really good product, have dropped out because their supplier has ceased production.This is a serious problem for us Bronica bugs.