I'm not quite sure whether you mean the rubber seal or the plastic / black colour on the doors - if it¨'s the black part: Have you tried to find some at a local shop that makes signs for shops etc. They usually have lots of different materials and qualities - worth a try....
As for the rubber - how about a Secondhand dealer - is it Scotty here on the Forum (can't remember the name) he might be able to help!
As for the rubber - how about a Secondhand dealer - is it Scotty here on the Forum (can't remember the name) he might be able to help!