installing seals on the roof rail, what type?

I have a question to ask and also a ***** I own a 67 barracuda notch back and I have been working on sealing the air leaks around the doors sinse the cold has set in and the first thing that I discovered was that there is a rubber type of sealer installed underneath the stainless side rail. does anyone know where you can get this stuff? the ***** that I have is that the side rail weather strip seal made by soft seal is to fat and will not fit in the molding like it is supposed to. Has anyone else experianced this?
Pat Faley
67 NB S Clone
Peoria IL