Welcome to the forum, looking at the amount of work your Trusty needs I think the 30 day trial will need converting to paid membership!!!! That style of bumper is the early one, forum member trusty220 will be able to give a more accurate date from the serial number. A Zenith carb for the engine should not be too difficult to find, gearbox side plates might be more difficult. The wheels seem to have seen better days too. Keep us posted of progress.