It would be great to hire a Morgan for the trip as at the end I'd surely know whether I could live with one but the cost seems prohibitive.
John Macdonald, near Durham, has a +4 for hire - not too far if you're going to be in Beverley.
http://www.macdonald-racing.com/Pages/Morgan_Hire.htmlI've had a chat with John at Allon White and he thought they could gain an inch or so through lowering the seat and using thinner padding
It's Sean who does the trimming and yes, they can make a thinner seat base which would help. But you may not have the option of removing the wooden blocks froim under the seat runners, as the later cars don't have them.
You could also consider a removable steering wheel which may help a lot.
Enjoy researching!
Nigel