Manton, I see in your first photo that you chose a black belt (and footwear, obviously) with the 'suit' combination. I understand that it dresses up the look, but with my own "Blazersuit" I could not get to grips with the black leather and horn button contrast. Perhaps I suffer from OCD but I much prefer the look sans-belt and with black shoes. Would appreciate your thoughts on that.
I worried about this a little bit. And, all things being equal, I prefer the suit with brown. But I think it works with black, when necessary. Honestly, the brown buttons don't look that incongruous.
After some trial and error, I settled on a cuff circumference of 9.5". The RTW standard is 10". That's also the typical baseline for MTM -- start with 10" and add (for a watch) or subtract (for a skinny wrist) from there. I went down to 9.25" once but I found it too tight, and the sleeve did not fall all the way down properly. 9.5" seems to work, even if it is unable to defy gravity, or the other three of the universes fundamental forces.