Maybe I am overly simplistic, but could not a two-pole, single-throw switch be ganged (connected together so that a push of the switch closes both contacts)?
Why a single master? The Split Master works great and very easy to treat as a single switch. There are circumstances where a pilot my want just BAT or Alt as power source, like an alternator generating excess power.
Thanks for the reply’s. Current master switch has an interm issue. We have tracked it down to the switch. I already have a alt switch. Just looking to replace back with the same switch.