I found this company who seem to make everything. Maybe handy for window seals, T-seals etc.
http://www.fastgaskets.co.uk/index.html
Contact details seem to be missing, I found them via Ebay. Contact details from Ebay:
Phone: 01782|813413
Email: fastgaskets@btconnect.com
Michael Owen
Unit 11 Brownhills Business Park
Canal lane, Tunstall
Stoke-on-Trent
Staffordshire
ST6 4RP
United Kingdom