I'm looking at an EAB aircraft for sale that was donated to a charity. Registration expired a few years ago. Seller has the logbooks, original AW certificate, and builders manual. Seller will not provide an FAA Bill of Sale, for reason that it has been deregistered. Without an FAA bill of sale, what would be involved? Is it possible to rebuild this aircraft and obtain a new EAB certificate? I would be looking at making changes to the configuration anyway, so can the process start over?