Hi Earthmother
Ally has said it all really, just my two penny worth, if the boatbuilder did not supply all the relevant stamping, certificates, manuals when the boat was moved to the broker, what else has he forgot.
I have seen all the paperwork that should come with a fully fitted RCD compliant boat and it filled an A4 boxfile.
Be advised by your surveyor, from what you have said he seems to be a good one.
You went down the sensible route of getting a surveyor in the first place, stay sensible.
I think you have already made this decision and just want some support, which you have.
Good luck