As your finding out, the sedan application is completely different than the other Dart / Valiant applications and with it being a 67 year model, you just further added to the complexity of finding all of the seals. No one vendor makes all of the seals available for the sedan applications and will require sourcing the parts from someone like ourselves and possibly Danta who would source these parts from us and the other manufactures.
If you should decide to go the route of changing out the reveal trim to the 68 and up style, you can use the Precision windshield gasket and Steele offers a rear gasket. Door seals and glass channel run kits can be sourced from Restoration Specialties. Window felts are available in the Top Cat brand which are duplicates to your originals. Clips and fasteners for the reveal trim can be sedan specific which we stock as well.
For the glass itself, that is going to be more difficult to locate than the weatherstripping. Finding new glass I believe will be just about impossible and good used will be a challenge as well.
If you should have any questions, drop me a message and I will send you my contact information.
Thanks,
Richard