Good point actually, I never did a weight comparison. I very very much doubt you'd get a weight saving though, the standard frame obviously works as the airbox which is quite a good piece of design work. The wall section is also very thin so again.. I doubt you'd beat it with a tubular construction. In terms of this specific project I'd take an increase in mass for a decrease in stiffness
You’ll be living in Hinckley then, you have my sympathy (I’m from there originally). That frame is absolutely stunning mate.