I am not sure of the difference, but there must be a significant difference as Chrysler lists a different part number between the convertible application and the others. The factory part number for the convertible application is 2424 392 while the hardtop / sedan application uses a 2242 450.
I know from some of the B-Body applications, the convertibles have more of a rake for the front windshield which requires a larger piece of glass and thus a larger gasket. I did not check the NAGs number to see if the glass might interchange, but for whatever the reason, Chrysler chose to use a different gasket for these applications.
If the glass is out of the car, you might be able to take some decent pictures of the profile and forward them to Steele Rubber to see if they might have a similar profile. Restoration Specialties and Supply also offers some different profiles, but the problem in going this route is that your unable to make the corners and would have to bond the materials to the existing corners.
Hopefully with the provided part number, you might find that needle in the haystack and find you a gasket.
