That charging plug you pictured is a three conductor deans and it will tell you nothing about any manufacturer. It comes from a time when deans were popular for modeler to use on all their equipment. Even replacing the hodge podge of different manufacturers plugs on radio systems. At on time their was a hugh variety of plugs in use.

That on board system is simply a switch and is not a modern on board electronic system. Is there a need? In most cases you are better off learning your engine better and on board glow is crutch that will only cause problems.

I hope the battery that the schematic refers to is not the RC system battery.

I have not seen an Aristocraft or Expert servo in use in many years Are they three or four wire servos and what kind of plugs are in use, You are bound to run into problems there.

John