Yes John you've been an amazing help; I can't thank you enough for all the information and support thus far!
However, I would love to 'dispose' of the roof for you! I think it would be an excellent item to help resurrect my Estate; I'm sure I can make good use of it. Would you be able to contact me directly please and we could go from there?
I think I'll weigh up my options before I truly decide to go down the GRP or steel roof, both have their pros and cons at this stage.
Regarding the roof seals I might have a few ideas as to how I could replicate them, and produce something that looks better than the 'Universal' fitment ones discussed...