I'm a bit confused with your situation...
I guess you have some electrical components from a later AS that you wish to install into your
1960?
I'm not 'up' on the wiring of 60's vintage trailers...however, I would think they would have some kind of fuse panel or terminal block for the various
12 volt circuits to be attached to the battery (s)...
A converter/charger is nothing more than a
12 volt 'source' of energy for your trailer when it's plugged into external 120 VAC power...and as such, the C/C's
12 volt output wires (POS & NEG) are hooked to the fuse panel, directly to the POS and NEG cables coming from the battery, through 50 amp fuses for each cable...
I'd try to get a wiring diagram for an older AS to help guide you through the process...
In any event, you'll have identify what each of the 'wires' you described are hooked to, what circuits, etc...which are POS leads and which are NEG (if any)...
A cheap digital volt-ohm meter will be a big help to identify you wiring circuits, etc...
Ray