Kip - You are right. If you had any kind of rubber weather striping around your doors, it was not original. The 41-46 trucks have a windlace around the doors which is held in place with the trim molding that's around the doors.
Any of the vendors will have replacement windlace for your doors. You can get either rubber or a vinal wrapped version. Check out their catalogs, some of them have some pretty good pictures of where it goes.
As for other rubber parts, ie front and rear window gaskets, I would recomend Steel Rubber. They are not the cheapest but they have the best products that arn't going to turn to dust in 2 years.
Good Luck
George
