Well, today I gutted the Campy hub and the Shimano hub, being careful to not mix stuff up. My findings...

The Campy cones do not fit the Shimano axle threads. The lock nut does, but only because there are not enough turns to compound the fit.

I installed the Shimano axle, cones, spacer/washers and lock nuts. The cones were even fitted with rubber dust/debris seals. I adjusted the ball bearing fit to darn near zero clearance and all seemed good. I plan to take the complete axle assemble, which is plenty long and sports generous thread lengths, to Jamaica with me. Once installed, successful or not, I will get back to this thread.