Hi everyone. I received an update from Omega (specifically the Swatch spare parts department in NJ) this morning:
"The part number for the [chronoscope] clasp is O117STZ013899, this is on backorder 4-6 weeks after the order is placed and retails for $211.00 plus $10.00 ground shipping and applicable sales tax. Please be advised that clasps are not interchangeable between bracelets."
So this confirms the part number and price Iowa_Watchman mentioned above. What remains unclear is exactly what "not interchangeable" means. What we really need to know is whether the Chronoscope clasp can be physically and securely attached to the 3861 Moonwatch bracelet, albeit with a bit of side-to-side overhang due to the 1mm difference in width, and what that will look like.