O.K. Tim,
Here is another idea which I hope will help you. A group of M3W owners from Smogmog (the London MSCC centre)bring their 3 wheelers up to the N.Norfolk coast in the summer for a camping trip.
Although they have the original cars, maybe they would be able to give you chapter and verse on what they do.
In case you aren't a MSCC member, the contact e-mail is;- morgansinthemews@gmail.com.
Good luck, hope you get a solution.
