Robin, I cannot cover all of your questions, because I don't know all the answers, but here goes.
I believe there is a log book about what was done and when on every car on the property. If you look as previous work session pages, you will see survey crews that check every car each year to keep track of where we are on what is needed on each car. From their reports, the planning committee decides what needs to be done, and when on each car.
EVERY car on the property belongs to the taxpayers of NM and Co, the Friends are only the caretakers of the equipment. When we are finished with a car, it is inspected by the railroad for being roadworthy, and if it passes, it is put on some sort of roster of cars available for charter, such as Jay's Chama Steam.
As for the number of cars under the new cover and the funds, it will depend on the size of the structure, and the number of tracks. This is all more of in the idea stage now, and more will be known as it works through the approval process.