Any advice? Garrett Master Hunter

Saw this at an auction one day and the concept kind of kindled an urge... And... Well... The Mrs bought it for me..

And then I picked up a new Patriot.. But we won't discuss that.

Back to the Garrett. Hadn't been able to nail down much information about this one. It's non-functioning. I'll be sitting down with it soon to fiddle with, but the lack of details makes it a bit difficult.

Anyone have any advice on where to start? Bonus for wiring schematics.. Not like it's hard to trace, though.