I have a Myers 3/4 HP J711P submersible pump installed in 1990 that ONLY supplies 1 outside spigot for watering the lawn. The inside of my home is municipal. I recently installed a schrader valve so I could pump air into the big old galvanized tank. That really helped reduce the cycling and it has been working great. Just last week however, I noticed that my PSI was dropping fast with no spigots open. The pump seems to still be pumping fine though. I believe that my check vavle by the holding tank failed in the open position (does that sound right?) According to the pump manual, the pump also has a check valve installed at the top of it. I thought now may be a good time to install a new smaller bladder type tank and put in a new check valve. My lines are galvanized steel.

First, what tank do you recommend? Remember this is just supplying 1 outdoor spigot. The tank currently has an air volume control, can I keep my current Square D pressure switch though? I am pretty handy but would like step by step instructions for installing this. From what I can see I just need to do the following...

Remove old tank and lines
Mount new tank
Install new check valve
Install pressure switch and PSI gauge in new tank
Hook up electrical to pressure switch

Is that all it would take?

Below is an image of the existing install...