I got these in job lot and they were in a bag that said 'RZ' on it, but they are not RZ gears as nothing in the RZ 'box has a 13mm shaft. I reckon they are 100 or 125 gears, maybe even from a 50 or 80.
The guy they came from had RZs and RGs, dunno if that helps.
I expect someone will recognise them... if you do and you want them, come round and pick em up
