DonL
Jack of all trades Master of one
Keep it Simple. . . Install a Cycle Stop Valve http://www.cyclestopvalves.com/index2.html. It'll extend the life of all your well/pump system. A Pside-kick http://constantpressurekits.com/products/pk1a. would be even better and it includes a new tank, pressure switch and all necessary components for your irrigation system. I'm not their salesperson but I love the valve.
I agree that would be very nice.
But I do believe if it is not broken, then don't fix it until it is.
I was Old Schooled.