Well that is great news. I don't mind the stains ( they are not rust stains). Think i will get it re caulked this fall. The last caulk job only lasted 2-3 years before cracking really bad. I know it was a two part compound they mixed on site.A good plaster job should get you around 20 + years. It wont be pretty but it will contain water. Some of the staining could possibly be acid washed. Either with a acid brush, wich pumps acid down to the head or you can lower the ph in your pool and scrub them. Depends on the stain. If its rust and looks to be in lines that is the rebar. If closer then 3 inches to the surface of the gunite it will bleed threw. Tend to see that on walls more then floors. Also a citric acid like stain eliminator might do the trick. If you dont care about it be super crisp looking I'd say you should be good for a bit. Especially if you dont have any tile falling off or anything.