That's very kind of you. I looked on Hobbies site and couldn't find them but have found other suppliers of timing pulleys and belts. The ones I got from SHG were XL pitch pulleys and, although I don't know what that means, I can replicate them from elsewhere. The main problem always seems to be getting the right bore but these seem to come with a pilot bore which means I can drill and ream to my requirement.
Thanks again for the offer but as I don't need them at the moment, just thinking ahead, I will try an online supplier. Also, if your workshop is anything like mine, you could be looking for some time!
All the best,