I would guess that when Farnier Pennin were making sun roofs they would have bought in the seals from a specialist manufacturer of rubber seals and profiles. I was going to attach a catalogue but it's too large so try going to the web page below and use the link 'Profile Catalogue ~ Click to Download' in the centre of the page because it could be worth trying to match the profile of the seals fitted to your vehicle with any available in this manufacturer's 2013 catalogue.
It has the added benefit of all the available seals being dimensioned and so you can hopefully not only match the profile but also the size.
http://www.emkablog.co.uk/products/gasket-profiles/Martin