I haven't tried the Avenir Sticky Fingers pads. For me, the advantage of KoolStop pads is the tremendous variety of shapes they offer. I've bought three or four sets of the replacement pads they sell for old Campy (and other) brake shoes:
Assuming the shoe is open at the back, you just slip out the old rubber and slide these in, for a look that's as close to authentic as you can get.
I tried the salmon pads on my NR brakes on my Raleigh, but couldn't get them to stay quiet, so I bought the black ones. The black pads probably don't stop quite as well as the salmon, but the racket was driving me nuts. I did wind up adjusting toe in by bending the arms slightly with an adjustable wrench
. Probably should have tried that with the salmon pads.
The Avenir sticky fingers look interesting and look like they would fit.