Answer from the seller on ebay:
Greetings Ernie!Ah, how are things in one of my favorite countries to visit? : )YES, This is a very rare derailleur!“Question: where does this Front derailleur come from?”On which bike it is mounted.A little history on it.It came out of a bin with someone who was...
The distance is different from center to center:
700: pin left round 6mm, right 5mm, outside outside 25.5 gives 20mm
735 and 650: 6/4,4/24=18.8
651: 6.3,3/23.7 = 19mm
Today or tomorrow I will do. There are more differences: Bolt is 6mm allen in stead of 5mm. The clamp is a little difference. And there is no number on the place where the derailleur touches the frame (Normaly. 1 1/4 of 1 3/8 at the inside.
I have this front derailleur. I also do not see it in any catalogue. My version is from feb 1986. Also thought it is rebuilt with a newer XT version endles clamp part. But I have not found a newer one with H--L on it. So I think it is really origional. Greetz Ernie from Netherlands