Sounds like it's been taken out to fit an old style headset. 32.7mm
http://sheldonbrown.com/cribsheet-headsets.html
http://sheldonbrown.com/cribsheet-headsets.html
matt24777":2a492avj said:LBS reckon the fram has had some machining done as there is a small lip about 20mm in from either end of the headtube.