Hornlaw, I wouldn't have a problem with purchasing a pre-owned corvette that had a part replaced, keep all documentation from the dealership in case you decide to sell it privately. I read on this site that the Chevrolet dealers mechanics who perform maintenance on the C7s had to attend GM training. Did the mechanics working on your C7 attend that training? When you get you C7 back, put it up on a lift to do a visual inspection to make sure everything was put back to factory specs, attention to detail.
Semper Fi
Rick
Semper Fi
Rick