Thanks for the info, I couldnt find anything but looks like I didnt look hard enough! From the other posts it seems like they were around in the 1960's, wonder when they stopped being supplied? The wiring is oldish plastic covered so cpuld be original..
I thought the construction didnt look quite commercial but its not badly made. Unfortunatly its been dropped which badly bent the large pulley. Dont want to risk breaking it so considering boring it true and bushing back to size.