Thanks, Sarah, and some nice "iron" there. The last picture, labelled "Campagnolo Sport," is of one I had not seen before: a single pulley unit with a sheet-metal body. I understand that there were some who thought single-pulley derailleurs would have significantly less friction than 2-pulley ones, and I have one of the "higher" quality brass/steel single-wheel Sport units, but I've never seen the Campagnolo name on something quite this stunningly, yes, I'll say it, "cheap looking."
Ah, for the good-ole honest Huret Svelto!
harvey sachs mcLean VA USA
http://flickr.com/
peace
sarahgibsonkansascitymissouriusa