It's a hard knock life: My vintage lightweight Tweed Run steed.

..a Simplex mech can still be fitted (if desired) and no-one will be any the wiser, but at least you can use the superior (IMHO) NR rear mech.

I think the older all metal Simplex to have a wider range and greater change reliability than early campagnolo, but each to their own. They don't half fetch a pemium on teh bay though :(