Weather Stripping?

You might also contact Steele Rubber. I was just watching My Classic Car last weekend and they had a rep from Steele Rubber on there saying that they custom print catalogs for people based on their individual cars for all the parts they offer. They also have a bunch of universal options for weather-stripping in case they don't carry what you need.

I just did a quick search for a '66 Dart Hardtop and a bunch of parts came up. I didn't see roof rail seals, but it may be worth contacting them and seeing what they have to offer.

www.steelrubber.com