Originally Posted by T-Mar

27.0mm post would be indicative of Columbus SP or another high grade imperial tubeset. Since the headset is not installed, remove the fork and check the outside of the steerer tube for the Columbus dove logo. If present, that would confirm a Columbus tubeset. If not present it could still mean tretubi SP but there is further means of verification without stripping the paint,unless the steerer tube has another manufacturer's logo.

The relative lack of brazed-on fittings and long droputs with eyelets suggests its no newer than about mid-1970s. I haven't seen any Concorde from this period and based on the decal font, suspect they may be later additions. Regardless, all the Concorde models I've seen were contract manufactured by various sources.