Actually a caboose is much more difficult to maintain. They were built in a way such as to replace stuff like flooring, you need to take off the interior siding. Of course to get the siding off, you need to take out everything on the inside. If goes on and on.
Until a few years ago, 0503's maintenance was the responsibility of the operator, as it was available for charter. It's had various repairs over the last 15 years, but really needs a major overall, particularly in the cupola area. A project is scheduled this summer to start that; it's unknown how much work is needed until they start removing the siding in that area. Plans are to have covered shelter in case the work turns out to be extensive.
This summer we should finally complete 0579 and have it certified for operation. I've documented this restoration over the last 8 years and with a little luck, some good volunteer help, and a bunch of money, we should have it ready this summer (including reconstructed caboose trucks). Please contact me offline if you want to help or send money !