What I forgot to mention in the list are the Marine Nationale battleships, Richelieu, Jean Bart, Strasbourg, Dunkerque, and Surcouf submarine cruiser. Even if the kit is now some 50 years old, 1/400 Richelieu is way superior in terms of accuracy than the 1/350 Trumpeter model. There was also a large series of sailing ships, some of them are still considered today as the best ever designed. Same for 1/200 scale that was mostly for civil ships.
It seems that at a certain moment, there were considerations to produce US Navy ships, but there was a change of owner at the same period and the decline of Heller then began...
Heller is now a shadow of its past glory, "new" offerings are only re-re-releases of old molds, only a few products are new in the cars series or re-boxings from other companies.