John Proch asks "...Has anyone out there had problems running 1/8" chain with a Campagnolo Gran Sport front derailleur? I don't have enough room barely to not have rub on my front cage. How was it done?..."
I've experience with that situation, though not with that specific front derailleur. For me it was a Simplex lever front derailleur on my Sun Manxman
http://www.peterbrueggeman.com/
I used a spreading pliers to widen the derailleur cage where it was too narrow for the 1/8" chain, and then wide-headed pliers to finish shaping the derailleur cage. That front derailleur now works fine with a 1/8" chain.
My experience is that adjustments on many old front derailleurs can encompass derailleur cage bending and shaping to improve alignment, shifting, chain pickup, etc. A derailleur cage that is amenable to such shaping would be flat-sided and pliable.
Peter Brueggeman
La Jolla California USA
4peebee(at)peterbrueggeman.com