I'd rather spend my money on restoring a TR than fitting that body on one! Also..."Hathaway Hunter" don't quite roll off the tongue as well as "Morgan"...sounds like some king of old fashioned pocket watch!
"It's a 1964 Triumph TR4 re-fitted with a Hathaway Hunter body and Laycock de Normanville overdrive"
Maybe it doesn't roll off the tongue easily, but I'll enjoy saying it.