Rear brake shoe, white round sliding pads

[Zeno]

Currently renewing the rear shoes (one set cracked across the center rivits) and need to replace the 6 small white round 15mm dia plastic sliding pads that the shoes sit against fitted into the rear wall. Some are broken and others have heavy indented slots.
Have searched the bay with nil luck. Any body know where I can get these, apart from the main dealers ?

[Zeno]

If anybody needs it, the part number is 6N0 609 589 description is Guidepiece.
Info kindly supplied by RUM4MO.

[RUM4MO]

Cough Cough, Glide Piece.