Greg, as you know I'm a woody boat guy first. However, my design preference is for offshore performance boats and my production boat of choice is Donzi (not a pre-war CC kind of guy). So, given the Wynn Mill history through the 16 and the story of Donzi (or just Wynn-Walters), I have been after a boat that fits in this wood/performance group for years... to crown my "fleet".
This is why I bought my 16 project and planned a wooden deck. I felt bad about cutting up an early boat and still not having exactly what I wanted so, I sold it). I have looked endlessly for building plans of these boats(both in NA and the UK), including contacting Naval Architects to reverse engineer/design plans so that I may build the boat I truly want. This is why I still look for a Formula Jr. or a replica (which I believe is closer to the original concept).
Along with this quest has come a lot of research. None of which tells me that any boat is identical to a Donzi 16, let alone one of the early racers I covet. Of course these boats are similar as the designs evolved from the same mind, with the same purpose.... and the engineering evolved too, just like race cars evolve with lessons learned at the track. So, maybe Thunderbox was further along the evolutionary chain of the wooden era but, I think it is a totally different branch of the same tree that grew the Donzi 16.
There is no evidence that Walt/Jim/Don took the Ski Sporter line drawings to Souters for them to build. It is a nice dream and possibly wishful but, totally unfounded. Rather, Souters had plans from the original Wynn Mill II. They planned to build boats in England for sale but, this thought never progressed. Despite this, the WM II designs were available and many variations were built by several builders trying to be competitive on the race scene. Emulation of winning designs is common in all forms of competition. Thunderbox is a modified version of the WM II plans, not a wooden prototype of the Ski Sporter.
Sean Conroy,
1964 Formula Jr. (hull #2) project
1972 Greavette Sunflash III
1981 Kavalk Mistral project
"A man can accomplish anything... as long as he doesn't care who gets the credit."