There is a Legnano auction on Ebay that recently closed. In the second picture, you can see a right-hand shifter (a Gian Roberts) placed on the seatstay, just above the brake bridge. It appears to be a clamp-on shifter, but I cannot be certain of that. It's the first time I have seen such a placement and wonder if any members know whether bikes and shifters were designed for such placement.
You can see the auction at the following: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190270309835
Chagrin Falls, Ohio USA