Found some shims that Exposure do that will fit 25.4mm. I think I'll be putting some bartape on the tips of the extensions so maybe a 1.6mm of tape will suffice filling the rest of the gap.
I've also used a "Space Bar" clamped to the base bar that extends downwards so I could then clamp my Exposure mount to that. It just cleared the headtube on my TT bike. You could borrow that mount too.
Found some shims that Exposure do that will fit 25.4mm. I think I'll be putting some bartape on the tips of the extensions so maybe a 1.6mm of tape will suffice filling the rest of the gap.