The 359 is an accessory 400-card TYPE panel with 2 slots. Note the TYPE, that means it will slot all sorts of 4XX cards, like the 401, 403, and a bunch of other special purpose cards. It's all in the wiring. Good luck finding one.
By the way, what Ken calls a spin-wrap tool is also called a wire-wrap tool. Radio shack used to sell them, with their shift to mainly consumer type stock, they probably don't any more. Maybe Sandman has them in stock. Used to be a very common type of connection method. I saw the inside of a Cray computer once that was built in a circle. If you looked down inside from the top, it looked like an electrician's nightmare, because the wires were as short as possible. That meant zillions of wire wrap jumpers going ACROSS the 'tube', top to bottom. (Get it right the first time, because won't get a 2nd chance!) You need to practice a little before you do it for keeps. And stranded wire is a no-no. So solder or scotchlok some 24 gauge wire onto the stranded headset cord. And you may have to use smaller wire, depends on the tool you get. John C.
