Hi Jeff/John,
I replaced my windows early this year - tried Clark Rubber, waste of time.
Grippy Rubber is the only place to go for Rubber products. Inexpensive and helpful.
They are at 28 Vore St. Silverwater and 98989688
Make sure you get the profile right.
Good luck
You will need 2 people to put the windows in and lots of patience.
Cheers
Rob