All looking rather sexy Mike! (The bike, not you.)
Going back to your comment about not much you can do if the disc mounting faces are too far apart, or wide; It might be possible to mount the disc(s) inside out with the offset the hub side to kind of make negative offset?
There would have to be enough room for the spokes to miss the calliper of course.
I'm assuming your discs are non-floating, unless they float without bobbins somehow? Rigid front discs are rather unusual these days?
I take it that you simply used a Triumph sprocket carrier? I hope you can line the chain up okay and the tyre too.
I was looking at my six heavy steel drive pins just the other day and thinking how much weight I could chop off with Ti replacements.
Every time I have the wheel out I look at the pins and bushes and put off replacement till another time.
The bushes and pins are quite expensive, I've looked into Polyurethane bushes which would be far superior, but have never found any, they are available for other models though. Poly bushes and Ti pins would be the dream if I had deeper pockets.