Hi Hammerhead,
Horn going off when turning the wheel...first thing that occurs to me is that is local to the wheel. There's usually a contact or two under the steering wheel pad that activates the horn. If the frames or springs have been bent out of shape or broken (say from someone banging their fist on the steering wheel, while cursing our the driver in front of them) that could cause the issue you experienced. Usually you can just pull that big padded cover off, (usually there are a couple of friction pins that hold it in) but go slow and carefully so as not to break anything. Once you can see the switches, you should be able to tell if they are damaged or making contact on their own when the wheel is turned.
Rear window could be a fuse, or the motor itself, both relatively straightforward and easy to check. Hopefully the rear window is stuck closed and not open.
Neither of those problems is necessarily an indication of an overall wiring problem. Are there other weird electrical things? Lights going on and off by themselves? Gauges that sometimes work and sometimes not?
One advantage to having an older car like this is that the electrical system is likely to be just basic connections, and not controlled by some central computer like in many modern cars.
I have a friend who is a mechanic here in town (in Magnolia though). He's been in the business awhile and I can ask him if he has any recommendations for a car electrical person/shop.
Checking the horn switches and rear window fuse and motor are pretty easy for any mechanic to do though, and I suspect you could start with that with any local mechanic you feel good about without breaking the bank. If you can tell them what you want them to do, they should be able to give you an estimate before they start.
I'm down near Morgan Junction. If you're close by or want to come down, I'd be happy to take a look at it for you, too. My user name links to my email.