Used longframe patchfields for free? Sounds good to me!
These are TRS patchfields. The third terminal is "ring", and it will be required for balanced interconnect: signal + goes on the tip (pin 2 of an XLR), signal - goes on the ring (pin 3), and signal ground goes on the sleeve (pin 1).
It sounds to me as if these patchbays are a little bit less useful that you would like if they have only three lugs per jack: that means they are non-normalling jacks. A normal-capable jack will have 5 lugs: tip, ring, sleeve, tip-switched, and ring-switched. The two "switched" lugs are connected to tip and ring, respectively, whenever no plug is inserted in the jack. That "normal" connection is broken whenever a plug is inserted. This normalling arrangement allows you to establish a default connection (using the switched contacts), so that signals can take a default path with no patch cables in place.
Your non-normalled patch bays will require a cable from jack to jack on the front side to establish any connection. But they are still very useful, and the price was certainly right...
If you look at the jacks as they are installed in the bay, you'll see that the bottom ones are rotated 180deg. This means that you can't just wire top to bottom in a straight line: for each pair of jacks, the order is reversed on the bottom jack: the lugs will go t-r-s on the top, and s-r-t on the bottom. So if you were to interconnect them, you'd end up with wires crossing in an X.
Since these are non-normalling jacks, you probably won't want to wire the jacks together in any case: You'll just terminate all three points (tip, ring, sleeve) onto a shielded pair cable that will go to the input or output of choice on the board or output gear. To help any more with setting up the bays, we'd need to know what your rig looks like, and what you intend to put in there... But normal switching surely would be useful. Perhaps you could ask your buddy if he has any of those?
The bay with all the sleeves commoned together may present you a problem, and it may not. There are two commonly used grounding schemes in audio production: one (often used in studios) uses the mixing board as the common signal ground point, with all other apparatus grounded to it in a star arrangement. The other, often seen in broadcast use, is to use the patchbay as the common signal ground point. That one bay was set up for that, sounds like. The reason that it might cause a problem is that if the grounds are all connected at the board, and *also* all connected at the bay, you just built in an ungodly number of ground loops, and you may cause yourself more hum-chasing problems that it is worth.
When you clean up the bay, you can remove the sleeve strapping, and just allow the patching to carry signal ground from the board common to all the peripheral gear. I've built patchfields both ways, and I vastly prefer to use the board as my common point. You pretty much have to go board-common with entry-level gear: it always has all the signal grounds tied together at the board, in any case.
I'd take an evening, heat up the iron, and desolder/clean up/tin the lugs, so that you could sit down with a bunch of wire and start terminating. You want to separate the drudgery of cleaning the existing wiring off the bays from installing your own wiring: otherwise, the latter will take _forever_, and not be much fun...
And don't forget to check out
https://homerecording.com/patchbay.html,
http://www.sigt.com/PP_Config_Guide.shtml, and
http://www.rane.com/pdf/note110.pdf.
The first is right here on the site, the second has good illustrations of that "normalling" thing, and the third has good information on how to handle balanced and unbalanced connections in and out...
