The Bird would be located near the two solenoid's in the link I provided, which is for a gas coach, and it would be for a diesel coach as in the 12v battery system link.
I never had a picture of diesel location, if someone reading this post maybe they could post a picture of where the Bird is located in diesel coach. I think the Bird system is behind a piece of velgro fabric in compartment drivers side near rear wheels with also a fuse panel. This link
12v wiring system may show that location.
There is Magnum inverter info in the QT's #3 link below.
The transfer switch will have your load center, Gen and shore power connections in it.
If you happen to have your shore line plugged in and your Gen was started the 50 amp power would transfer to the Gen power which takes precedent over all else.
Your Gen starts off your chassis battery's, in a gas coach Gen starts off the house batteries in a Newmar.
A stand alone battery charger can work off the outlet that's use for the engine oil heater its not off the inverter I believe.