Campy drivetrain, Shimano freehub

Hi All,

I know this sort of thing comes up repeatedly, but here goes anyway.

I am building a bike for my son and I have aquired some wheels which
have a Shimano freehub. These are aftermarket wheels. The bike has
Campy 10-speed Mirage/Xenon components. A Wheels Mfg kit is too
expensive for this bike. What should I do to make this work well?

I know I could build a regular wheel with a Mirage hub (if I could
find a suitable rim), or something like that, but these are "boutique"
wheels and they are the ones I've got for the project, and being a
funky size (540), they are not going to be swapped unless absolutely