Round Sound Machine Model 105 Hookup

[uhoh7]

So I finally had some time to open up a 105 I aquired as part of a larger deal. I haven't pluged it in, but it appears in good shape. The AC is independant. It has no amp of any kind. There are two speakers, but only the 8" woofer has a rotor. There is a 3 prong input receptacle, similar to what I see inside my 760. Each pin recieves 2 wires from the simple crossover/junction. I include the schematic.

1) Is this a balanced or unbalanced input?
2) What pins do I want connected for input from a simple amp? IE let's say RCA cable.

I have a NUMA C2X I'd like to try with the speaker :)

It was intended to be marketed for low end spinet organs that had no internal Leslie, so the input may include "half-moon" control.

Here is complete Roundsound 105 album on flickr:
https://flic.kr/s/aHsmEDUCdC

Thanks to all,
this forum has helped me so much. :)

105 schematic by unoh7, on Flickr

Mystery by unoh7, on Flickr