Sorry I missed this one. I believe the 10 GPM pump has always been large enough to handle peak GPM demands if there has never been a problem with low or no pressure. So replacing the tank as is should be fine. I do not agree that pressurized storage is a good way to handle peak demands which are higher than peak GPM of the pump. In Murphy's house, which I and almost everyone else lives in, the pressure will inevitably be at 41 PSI with a 40/60 pressure switch when the peak demand happens. This means that your tank is effectively empty and the only water you will get is from the pump. If you lower the air pressure in the tank it will only delay the bladder hitting the bottom by a minute or so. Lowering the air pressure also reduces the available draw down from the tank, so the tank actually holds less water and causes more cycling. Pressurized storage can only help with peak demands for a few minutes, even if you are lucky enough for the tank to be full when the peak demand happens. Water stored before the pump is always available for peak demands. Water stored after the pump may not be there when you need it. The high pressure sure did not help things but, I believe that the two pressure switches and the bladder was destroyed from cycling on and off. I am amazed that the pump still works and I would be sticking back at least a couple of hundred a month for a new pump as it can't be in very good shape from all the cycling. A CSV would help because the new pump you are going to need will not be as good as the one you bought in 1993. With multiple houses, the CSV will reduce the number of cycles considerably. The CSV can also help when demand changes from moderate to peak. During moderate demands the pump has already come on and the CSV is holding pressure steady at 50 or 55 PSI, so the tank remains ½ or 3/4 full. The CSV will allow the pump to reach it's maximum out put while still holding 50 or 55 PSI. So if demand increases above the max out put of the pump, additional water is available to be expressed from the tank as the pressure drops to 40 PSI. This will help for a few minutes longer than if the tank were empty when peak demand happens, but I still believe pressurized storage is not a good way to handle peak demands which are higher than the max flow of the pump.