I had no idea this site had a pools forum - fantastic.
My 35,000 gal. Anthony pool is 25+ years old, and looking worse for the wear. The pool has several issues, which the PO failed to address properly (I had no clue when I purchased). I'd like to run through the issues, then discuss the best course of action.
First, with concrete showing through the plaster, rather than replaster the pool he drained it and painted it. Knowing this guy, it was probably house paint that he bought on sale

. At any rate, its now worn off irregularly, and we can see the concrete showing through again, but with the added benefit of paint roller tracks layered over.
Second, there is a crack along the bottom of the tile line, extending for about two feet in one area. The tiles have popped off, and it actually appears that the beam has separated - it juts out about 1/2 inch. It actually does not leak though. The PO glued the tiles back on long enough to get the house sold.
Finally, the PO installed a stone deck over top of the original concrete deck, including right up over the coping. Its natural stone, mortared in, and it actually looks great. However, I've heard that this is a no-no since it (1) adds significant weight to the deck/coping), and (2) covers up the coping-to-deck seal.
At any rate, as I write this I'm realizing that its exceedingly difficult to help based on this limited description, but I'm wondering what your professional opinion is. I had an estimate of $30k to have the pool sandblasted (to remove the paint), replastered, retiled and recoped. This estimate did not include removing the stone deck, which is necessary before the project can begin. I could rent a skidsteer and do this myself, but damn its a huge undertaking, and a serious waste of stone. Since the original concrete coping seems to be intact, is it really necessary to remove this stone in order to refinish the pool?
Others have advised to simply let sleeping dogs lie, then just fill the pool in when it fails.
Opinions?