Thanks to Fuzzz for the downtube shifters. Further to the discussion Pyze and Mike and I had about cycling caps, there's some other pics here and if you go into the directory "cycle" there's a pattern with some instructions in pdf. http://james.architectureburger.com/cycle/cap.html

blickblocks has a thread going on it too: http://www.bikeforums.net/showthread.php?t=292333