Panel Truck rear door seal/ rubber - source?

[Apache13]

Hello Guys, have been reading through old posts....just found this forum in the last week. What a great resource you guys have here. I have and been driving my 1958 Apache Panel truck for almost 18 years now. Daily driver for years and maybe last 5 years just summer use. Have a very tight exhaust / muffler system and it is the same routing I have had for years..twin exhaust straight out the back by rear bumper. I have a 350 engine it is. But last summer and this year I have a real exhaust smell in the cab which I never had when I daily drove it for years. I am thinking it may be the old seals in the rear door are leaking dried up. I have looked around the net a bit and could not find a source for a nice quality set of door seals for the rear doors. The originals have these little pins that pop into the door frame that I am sure you are familiar with. I have seen some for sale classic parts but looks like it just some generic weatherstrip that you glue on from what I can see. What you others with panel trucks done? or source? Thanks in advance for any help.