I always though of the Z3 as somewhat of a spiritual successor to the Big Healey as well, if the Miata is the successor to the MG, the Z3 was the successor to the Healey, a bit more expensive, a bit more power, a competent, but not overly modern or sophisticated chassis. Even started with a 4 then went to a 6 cylinder. As far as "if Donald were still alive" regardless of what you think of the HMC, I don't think that is what he would have built, as already noted, though the relationship didn't last, he had already tried to move forward with the Jensen Healey, and that was in the early 70s, he wanted to build great cars by contemporary standards, not replicars, even if they were replicas of great cars he built.