Quite possibly! I've just waved a ruler at my stem and the bolts look to be ~9.5mm centre to centre, with a +/- or 0.5mm (it's dark and I'm using a steel ruler).
Same here (9.5mm)!
It would be awesome if you have any spare mount that will fit newer zipp stems so we can swap! I'll take some measurements tomorrow, but in case you don't sell yours or they don't fit, I'll just sell you mine.
Quite possibly! I've just waved a ruler at my stem and the bolts look to be ~9.5mm centre to centre, with a +/- or 0.5mm (it's dark and I'm using a steel ruler).