I routinely break a big rule, yeah, I have no problem using a Shimano drive train on an otherwise Campy Italian machine. This bike had Shimano 600 on it the first time I built it back in the 80s, now it wears 105 9 speed and a Nitto stem and Noodle bar.
It will rock Ultegra hubs on silver Mavic wheels, at least that si my current plan with Conti 23mm GP4000 tires. The saddle will be whatever I can find in yellow. I also need to trim the cables yet.
J