I have had a very small batch of late 1930s pattern gearbox tray clamps made (it was the only way I could get a set for myself). They are for pre-war frames with left hand brake pedal and cross shaft to brake rod. Each set consists of two matched pairs of clamps, machined in steel from original drawings. They work out at £45 per complete set if anyone is interested.
Regards,
Chris Wastell