If memory serves the Velo Orange headset has a tall stack height, more like Campagnolo NR than the 32 mm or so like an old Stronglight P3. The last time i had this problem I got a generic vintage Motobecane headset off the ‘bay - in my case I combined the top of that with a Tange Passage lower to accommodate a 26.4 crown. Allegedly, Motobecane used an OEM grade headset made by Stronglight.