1966 Dart GT-it begins

Resto Rick sells a great product. I’ve used it, looks right! Need several coats, let dry between.

don’t use bedliner paint on your classic car!

Restorations by Rick Kreuziger - Product and Component Restoration Detailed Information

Thank you for that and it sppears his undercoat will make it more OEM.
What I am referring to is stuff that appears to be smoothed out with trowel on the panel seams in the trunk. Surely its out there since they still do that on newer cars. Is it in a tube like chalk?

update: I guess Eastwood has brushable and tube types. Should do more research before asking questions. Thanks all who have and will help with this project.