Mechanical advantage of drop bar brake (only) levers (not brifters)

[NHAero]

As I fool around with the vintage-lite build of my '72 Bob Jackson I currently have a Paul Racer centerpull brake caliper on the front, which replaces the less powerful long reach Tektro 559. I currently have my old Campy NR non-aero brake levers on the bike. Are there vintage levers (aero or non-aero doesn't matter to me) that would have better mechanical advantage and therefore result in more braking power?

Also, the pads are black, not the salmon Koolstop pads shown in the current Paul web store. Would braking (dry conditions, I don't ride this bike in the rain anymore!) be improved by the salmon pads?