I recently ordered an Aeroad CFR replica frame from Aliexpress with fully integrated cable routing. The frame looks great, but the upper headset bearing size is 49mm outer / 40mm inner (as opposed to the more standard 52mm outer) and I am having trouble finding a replacement headset cover that will work with that outer bearing size. Correction: using more accurate calipers, the bearing is 49.5mm outer 40.5mm inner 6.5mm height, which appears to be the upper bearing used by Specialized for the Tarmac SL7 (perhaps among others). I've started work to modify the included headset cover to work with a separate stem and semi-integrated cable routing, but I would love something a bit cleaner that is designed to work with a 49.5mm bearing out of the box. Unsurprisingly, the seller does not have any suggestions.
For additional context, the FSA ACR integrated headsets and compression ring fit the inner diameter of the headset bearing perfectly with a tiny bit of play, but the headset caps are a few mm too wide for the frame because they are designed for the standard 52mm bearing.
Any suggestions would be welcome!