Add switch guards, correct DC BUS FAULT text in certain LM's

[rcflyinghokie]

A guard should be placed around the recorder switch and inverter switch.

It was noticed that the "DC BUS FAULT" text per the systems handbook displays seems to actually have been "DC FEEDER FAULT" in at least LM-6, 10, 11, and 12, with the text arranged differently on 10 and subsequent.