Hi SW,
Yes, I had one of the longer running Sencenbaugh's in this neck of the woods - up since '84 or '85. Took it down last summer and sold it, and another parts machine to doubledipsoon. I think I may still have another manual. He's got the original one IIRC. Is it 12V (1000-14 or 14-1000?). You'll need to know that.
Basically you have 3-phase AC between the machine and the controller, then two field wires that control when to start, and how much load to put on the alternator - similar to many auto alternators. The field wires are polarity sensitive, but there should be a +pos and -neg label at the panel. Then there is a ground wire. The batt + and - is just that; the load + and - goes to the DC loads, and each has its own breaker (big red reset buttons) up top.
IMO they are pretty robust and if your expectations are right and you have a good site it should serve you well. Keep oil in it, and blades finished - we did ours about every 6-7 years. Lightning can occasionally take out the control board, but Jim was still repairing them last I knew.
If you send a me pm I can probably send you a pdf of the manual.
~ks