Campagnolo went through a few minor revisions of brake levers in the middle 80's.

The first "new" set was for the Colbalto brakes, white hoods, a slightly revised main body to allow "aero" or traditional cable routing.
The aero way required filing a mouse hole into the upper body at the provided point or drilling the bars, they also required the often lost guide plates that fit into ports above the cable anchor point. In the aero routing configuration there was a bit less mechanical advantage compared to the traditional cable route. There was no quick release provision.

Later they added a quick release button and revised the geometry a bit. The quick release was a small cylinder button on the side of the lever blade adjacent to the lever body. You need those. There were minor finish differences between the groups. No return springs.

Return springs in the levers were a design feature of other mfgs. first, and were coupled with weaker caliper return springs. This set up offers a bit faster release of the brake, but is really very minor. The overall spring tension you are squeezing against for systems designed that way may be less. Campagnolo adopted this but much later.

Yes, you can use some other brand of lever with a return spring, but keep in mind that you are squeezing two springs vs. one.
For me the primary need with those calipers is a quick release in the lever as there is none in the caliper.