Ford engines do not have the vin number on the block just the part number and also a date stamp. Part number would be the Dove marking that you mentioned. There is also a date stamp found under the
oil filter block plate. It will read something like "6A21". Translated January the 21st 1966. It sounds like they want proof of the translation through the manufacturer. My engine builder has it all broken down on the paperwork of the engine he sent so maybe the DMV will accept that. Otherwise maybe a Ford manual from that period? I would like to hear from the others who have done this to see what they experienced also!