FJ also inspired generations of Trek designs, from the Freedom and Jupp classes of TNG and DS9, to the three-nacelled Enterprise in the TNG. finale, to the USS Kelvin and Spacedock from the latest movies. Perhaps even the idea of a Federation Dreadnought.
First, of all, I want to add that if anybody had been "ripped off" it had been Walter Matt Jefferies. The essential appeal and success of Franz Joseph's works is owed to the designs of Matt Jefferies.
Franz Joseph, Ballantine Books and Paramount Pictures had their shares of the profit, Matt Jefferies didn't.
Same with the "inspiration" you just brought up. The essential starship design was created by Matt Jefferies and all subsequent designs, especially those of Franz Joseph, were inspired by Matt Jefferies and derived from his vision.
Bob