Any question answered...

OK. I am trying to make an older Campag front mech work with a new SRAM crank (double). I can't get enough travel on the mech to get it to shift down to the smallest ring. I am at the limit of the limit screws.

Is it likely to be a campag/sram compatibility issue? Is a new front mech the only way to resolve this issue? or is the front mech indexing distance pretty standard and I am missing something obvious?

Not sure I understand the problem, the FD should have been initially set up with the chain on the inner ring anyway - If that makes sense.

Start again. Make sure the shifter has released all the gear cable, set the L limit screw on the FD so that the chain doesn't slip off the ring into the BB cluster, but also doesn't rub the FD cage when in the largest rear sprocket.

Once the L limit screw is set, pull the gear cable taut and tighten the cable clamp. You'll probably then need to tighten the slack using the downtube mount/guide.