Thanks KennyM. If I was not going to use LED indicator lights then the Auber SW3 should work right (Selector Switch, 3-Position Maintained 2 NO, 22mm)? Trying to save space on the enclosure so the indicators have to go. Just going to use tags and locate the switch as you have in your diagram.
My switch is a 2-position (HLT/MASH) but a 3-position could be used too. I used 2 NO and 2 NC switch blocks as I recommend switching both the + and - control leads from each of the two PID controllers. You could connect the - control leads together and save a set of switches but when I checked my PID controllers, the - control leads were not common with the power supply ground so I kept them separated. You can see all four of the switch blocks I used in the 2nd wiring diagram just above the HLT SSR relay in the thread I linked above.
Kenny