PREMIER AVIATION
1951 E AIRPORT RD
TUCSON, AZ 85706
Phone (520) 889-6327
Fax (520) 889-8249
Web Site
www.iwantcessnaparts.com
I ordered the window seals for my C337G in June of 2009 from this company for $5.47/foot. This is Cessna part number S2171-1. This is the seal that holds the inside window pains in place if this is what you are looking for. As for the door seal, I did not replace mine but I would bet you could get that here as well.
Hope this helps! Good Luck!
Ed