I recently emailed with Frans Dingemans, heavily involved in the SS Rotterdam's wonderful conversion.
The cost over-run on Rotterdam did not have to happen. There were a lot of delays, and a lot of politics. He said one thing striking "None of the parties involved - management, contractors and builders - were involved in the process of shipbuilding or ship restoration before."
I have also been told by someone close to it that "Financially, politically, contractually, commercially – almost nothing went smoothly or to the original plan".
It is vitally important that the difficulties on the project for Rotterdam don't become an excuse to not even try with QE2. They seem to come down to mistakes. I've been trying to get to the bottom of this recently without much success.
They knew the ship had extensive asbestos, if they didn't plan and budget for it, that was simply a mistake. QE2 has lots of asbestos, but they know exactly where it is, and exactly how to deal with it.
So, based on what I've heard and experienced myself, the finished product of the SS Rotterdam serves as a superb template to future ship conversions about how to do it right. How they went about it, however, probably serves as a template for how not to do it!