We may be in luck, i have just contacted a company here in australia called rare spares, they seem to think they can get their hands on them for $136 each side and window squeegees for $25 a side.
Id had lost all hope trying to find these, i was speaking to a guy who told me he wouldnt have a problem deleting the vent with a solid glass piece and a generic gasket, Thats my second option. I am trying to keep this car as original as possible so id simply prefer new seals.
Andrew.