They are not 2510 valves. They may be 2750 or 2500 valves. Considering the age of these units, you have gotten your moneys worth especially considering how bad your water is. The reason they want your wife there is because they are sending a salesman, not a technician, once you told them they were 15 years old... new equipment time to them.
I would recommend replacing the systems in the near future. You will be needing a complete valve rebuild, new media, new manifolds. The tanks and valve bodies are probably fine. Rebuilding these valves is relatively simple, I would rebuild/replace the injector assembly, replace the piston, seals, spacers, brine valve on softener, and replace the medias. The iron system "special blend" is usually nothing more than a couple of standard medias mixed inside the tank.