What about Suffolk?
Caterham has a successful case against Westfield so the legal precedent is there.
Suffolk were never taken to court.
Caterham was a current production car and their sole product was copied by Westfield. Not really a precedent.
JLR certainly do have massive legal resources but they were rinsed by Ineos which IMHO was a much more valid case. They may well be able to intimidate smaller companies into submission.
Intellectual Property Rights on the C Type have long since expired so even that statement is incorrect in the JLR open letter.
I should add that I'm a lifelong Jaguar fan - it's just that in this particular case I feel that JLR have badly misjudged things and to what end ?