If the boat is D027 it has been built between April 1990 and March 1991.
As Purple 21 wrote, each Phantom has it's own unique build number. If there originally was some sort of order document or build sheet for your boat it has most likely been misplaced a long time ago. As there is no official boat register in the UK there has not been any need to keep up with the paperwork, other than for insurance purposes. To my understanding there is no general official registration documentation available for Phantom boats or for any other boat brand for that matter. Even today the CE certification papers are for a specific boat with a specific build/serial number, you cannot buy the documents from some other boat... and your boat has been built way before CE certification time, so unfortunately I don't think you will find any official documentation on the subject.
I am not familiar at all with how the Spanish registration agency handles older boats, but I would assume they go by the EU standards. Up here north it works so, that if a boat has been in use, whether registered or not, within the EU, the only thing you need is a bill of sale which has the boat's serial number and build year on it. And yes, the UK is still part of EU at least for some time
With a new boat you need CE certification papers for your exact boat with s specific serial number.
To further clarify, here in Finland all boats with over 20hp engines need to be officially registered just like cars... so some form of paperwork is required. I assume the same goes for Spain...
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