Surprised no one has mentioned this auction [~ not mine]. A swell opportunity to practice your technique with this shifter, and on a lovely more modern frameset which was obviously built specifically to utilize that changer.
I would love to become expert with this mechanism, if only so I might casually remark: "oh yes, of course, well it's quite simple really. Let me show you how it is done..."
What fun for your next local vintage ride... or should I say "Race"?
Bob Hanson, Albuquerque, New Mexico, USA