I always knew that the Ace Craft 660DV is an amazing hull
Following a tip off by Roger Laxson who worked for Ace Craft, I discovered that this hull has remained unchanged since the 1960's:
It was designed by Richard Cole of Miami, and built by Botved Boats of Denmark, a family business with the best of credentials, spanning a few decades
Ace Craft started building this boat in South Africa, right up to 1993, when they went bankrupt
It is actually a Coronet 21, which is sought after until today. They were all built and exported worldwide by Botved Boats of Denmark.
Dudley (Anchor Boats) has the moulds if I remember right, and also knows something about this history.