I know the LancLancaster in Hamilton (Canada) is only flown occasionally (once or twice a year), due to the very high cost involved. I've had the privilege of crawling through it in the hangar, and it's special for sure. Although it's part of a fantastic museum of restored aircraft, there are never many people touring through (and generating revenue).......very, very unfortunate.
I live about an hour away, and a couple of times over the years I've heard a deep rumble approaching in the sky, and instantly knew it was the Lanc out for a flight. Can only imagine what a few squadrons of these together would have sounded like.