You seem to be admitting that the airplane initially must have an FAA certification and registration when it is manufactured, otherwise how coul it be de-registered with the FAA.
Answer to your question about the airplane in England. The airplane could not be exported from the U.S. with out an Export Certificate of Airworthiness issued by the FAA. The FAA would not issue an Export C of A unless the type design had previously been certified by the FAA and the airplane being exported met FAA regulations. The importing country, in this case England, would not certify the airplane and allow it to be put on the English register if it did not have an Export C of A from the U.S.