Does anyone recognize this headset??
 

On a Geoffrey Butler I just bought.

This is an old and heavy headset, which I would like to replace. Better get stack heights right though.

If you recognize this it would be a help - Thanks.

I see a Cinelli handlebar logo. I'll claim ignorance here and say I haven't a clue as to your question, but including some of the history and component details of the bike might help identify that particular part based on a similar built bike of the same vinage or an associate builder. I too have a quality vintage bike of mostly French components with an unknown bulky headset that might eventually be replaced. Good luck.

Possibly an English TDC. I know they made one that looked like that, but so did a Japanese company, I think. Do some research on TDC though.

Probably TDC, but the washer under the top nut looks Stronglight Competition or at least French due to the teeth. Tear it apart, upside down, as I am pretty certian the bearings are loose. It looks aside from the washer very proper on a British frame.

be seeing you

Yes, its mine ;)