I'm always fascinated to know how people raise Crown roofs, because the bodysides are far from parallel. Did you cut at the roofline, or lower down near the floor level? I thought at first about doing that with my bus, but two seconds later I realized that was not going to happen. To gain extra headroom in the shower I'm thinking of lowering the floor level there by a few inches, not easy but still doable compared to raising the roof.
My bus also has curved sides so I had the same problem deciding how to raise the roof. I also considered lowering the floor, but it would have been a huge amount of work and in some places it couldn't have been done at all.
I put the roof raise within the roof itself (rather than the sides) and then made up panels that continued the curve of the sides up to the new roof level. I'm sure that only by comparing my bus with one from the factory would you realise that mine wasn't standard. I was conscious that dealing with the curved sides would be progressively more difficult the higher the raise was, so I only raised the roof by 7". In retrospect a couple of inches higher would have been better, and wouldn't have made any real difference to the job - but I think Crowns have a greater amount of curve than my bus has, which would exaggerate the problem.