Great pics.
Thanks for that.
I would guess the inner bearing is just there to space the pulley out from the crancase.
The pulleys are all steel???
I thought they might have been alloy. Well the outer with the clutch on it.
Looking at the red ones i have here i thought they were alloy. Might have to grab a magnet and check.
I think my best option will be to buy another machine that has a complete clutch.
I would say the machine you have is a MKIII or something like that.
The red being MKI the yellow i have being MKII and the two on ebay and the one you have being a MKIII.
I suppose it would be interesting to be able to validate what im thinking above with the introduction dates of the other models Greenfields went on to make.