>From that Speedplay webpage David Bilenkey referenced
http://www.speedplay.com/
you can see the modern clipless pedal was invented in 1895, so they do predate the 1983 cutoff by a bit.
Still I vote for not discussing them here, because you can find endless discussion of them on virtually every other bike related forum. Not that anyone cares about my vote, and this is a benign dictatorship anyway not a democracy, but I think a classic bike loses something when you put clipless pedals on it. Is it really so awful to have to use period-correct shoes when taking your bit o' history out for a spin? Classic Rendezvous is no place for wimps!
Mark Bulgier
Seattle, Wa
USA