Parts for RBB easel

I swerved into ownership of a 16x20 easel, by a British
firm, later owned by Photon Beard, aka RBB, and I have new blades for it, but do not have the plastic guides
(thingys) that bolt to the blades and run in the guides to allow one to manipulate the blades with ease.

Anybody got any ideas about a source? I email Photon
Beard and they did not answer.

Hi Herb !
This is strange because in last autumn, I've buight a 4 blades Photon Beard easel (second hand from Mr Cad in GB) which was damaged on transportation. Mr Cad provided me with new parts from them. They told me they can supply spares parts for some time, still...
It could be worth a phone call ?