Well, that's excellent really, is it not? You have most of the parts you were after, and even if not servicable, it makes replacements a damn site easier.
I'm not sure exactly which thing you could not get off and took a chisel to. but it's all fairly basic and so should be fixable.
I'm glad you have the shape of the reverse friction piece now - the tricky thing with that one is to make sure the shape you cut is exactly centered or else you will end up with a slight oval rotating instead of a round disc. However, if you clean up the pulley shaft, you can make it bang on by constantly offering the replacement friction disc up to it as you go.
Don't forget that the parts from Chester Hudson are already round discs and have a central hole (albeit too small) to get you going. And you get two of them for £11.
I could not find a way of removing the grease nipple as it has no flats on it, so I think it may be pressed in rather than screwed in. I don't know. But if you put a grease gun on it and grease eventually comes out of the small hole, then I guess you don't need to do anything else.
Have you considered taking the large final drive V pulley to a fabrication shop (if there are any left in the country) and handing them the old one as a template to make you a new one up? I can't see it costing the earth. I do think you're going to need a bearing puller to get it off though as it appears to have a notch in it for a woodruff key of some sort.
I would have thought that any old wheels would do. Try looking at golf trolley wheels, for instance. I'm not sure about handlebars though - I think I'd be off back to the local fabrication shop myself.
Anyway, good luck and let us know how you get on.
Mike C.