Ok first you have a regulator and you have a change over valve. The rest of your post talked about the change over valve
The arrow points to the IN USE tank. for normal operation
NOW. so long as your only pilot light is the oven you do not need a change over valve. Just check valves. You hook up both tanks with a "T" (The T contains check valves) and open only one tank.. When it runs out you close it and open the other tank.. Now you may get a bit cold and Murphy says it will run out at 3am in the rain but.. That's how I did it.
