After several emails to 3M about availability of the sought after UK 3M backing plate, I finally got this as a response:
3M™ Finesse-it™ Contact Disc Pad 14738, 5 in x 1 in 5/8-11 Internal, 10 per case
[click to enlarge] For use with Finesse-it™ buffing or polishing pads and Hookit™ abrasives. Ideal for large areas. Has a 5/8-11 internal thread for use with rotary sanders with 5/8-11 external threaded shanks. Use with 5 1/4 inch buffs or 5 inch Hookit discs.
GTIN(UPC/EAN) : 0 00 51144 14738 0
3M Id : 60-9800-2658-1
Buyer's Part Number : 14738
Here is the direct link to the pad on 3M website:
3M Automotive, Marine and Aerospace : 3M™ Finesse-it™ Contact Disc Pad 14738, 5 in x 1 in 5/8-11 Internal, 10 per case
But I can't tell if it's foam or just rubber!!!!
Anyone have any clues???