You can try some of the local wreckers, they may have some bits. ALso, you can try your local Toyota Dealership, though some dealerships are better than others and these parts are getting pretty rare and TOyota may not stock them anymore.
Also, ask for what your looking for in the "Parts Wanted" area on Toymods. SOme people are wrecking old Celicas and may have the parts you need.
There are companies around who make window rubber seals and stuff like that for these old cars. I'll be off the PC most of today, but later on I'll have a look 'cos I'm sure I've got the name of one of these compaines on my machine somewhere.