^^^ Sweet!
Was that part of Campy's 50th anniversary set? I have a cheaply framed poster I found for $4 back in 1990 depicting a similar gold rear derailleur.
I don't know but your poster reminded me of something Mr S said about the 50th anniversary set... he reckoned the RD wasn't very good and laughed when he told me that the gold bolt head was only thinly gold plated. Apparently a few people have tried cleaning it only to have the gold plating come off.