If you can keep the Cub on the British register then you will be far better off rebuilding it under the UK Light Aircraft Association (LAA) rules. This regime allows for owner work to be signed off by an LAA inspector.
Go to the LAA website
Welcome to the Light Aircraft Association and make contact with them. I know of one chap who has managed, after jumping through the appropriate hoops, to get his LAA Permit renewed in Australia.