57 Overlander Questions

[uwe]

I need to buy a 1957 Overlander real bad. The bug has got me again.....
The seller mentions Hydraulic brakes? Did they have hydraulic brakes back then?
Umbilical cord? Does it have the Bargman 7-pin connection? Anyone have one of these 57's or been around one? What will I need to get this thing to light up at least, having the 7-pin round on my Tow Vehicle ( 1/2 ton Suburban) ?
The weight of the trailer is supposed to be about 3200lbs, tongue weight about 260lbs. Does this seem right? I got those numbers off the Airstram faq page.
Do these have a 2" hitch ball? What about hitch height?
Leaf spring axles or dura torque? It's a California model, dual wheels and slanted wheel wells. Too cool. Gotta get it.
Anything else you might think of that I need to know before getting this trailer would be appreciated. I am set up to tow a 1971 tradewind, which seems much heavier, with almost twice the tongue weight. Will I need my weigh t distributing hitch?
The trailer is a little ways away, about a day's drive.