hi guys ive had my mk1 clipper for a year now, but the poor girl has been sat on me driveway ever since!! 
but ive just got hold of a lock up so shes going to go in to storage to dry out!!
but ive noticed that the driver side front window scraper seal has warped and is letting water in, at the moment ive got duck tape sealing it!!
ive searched everywhere looking for a new/used 1 but i cant seem to find them anywhere!!
any ideas?? could i modify a different seal to fit?
cheers sean
Do mean the rubber highlighted below?

If so then don't fret about water passing through it, this rubber is not designed to prevent water going in the door, this applies to practically any car.
If water is getting in the car from the doors then you need to check the drain holes at the bottom of them as these being blocked is common. With the doors open you'll notice a couple of rectangular holes facing the ground. theses must be clear.
Also, with the door card removed, check the plastic membrane behind it, this must be in good order and sealed around the edges.

If it isn't, replace it.

Keep an eye on ebay or your local scrappy, the rubbers do turn up, more so for cabbys than tin tops. also try Crazyquiffs.