Starter Solenoid fried? '86 Ford Bronco ii 2.9L V6

Yeah it was a dumb mistake to be sure. We've all made them before. Lol luckily this truck was bought on the cheap for a summer project so not a whole lot of money went into the initial investment, but now... You're right though, about the negative cable, from what I understand about the starter solenoid on those model fords they're always enabled until the starter unit closes the circuit. In this case if the electrical flow was reversed then the solenoid would just burn up from the short along with the negative cable. I haven't had the chance to really get under there to look. Just looking for a good starting point. I really hope it stopped at the starter solenoid and starter (negative) cable. Thanks!

UPDATE: I went ahead and replaced the starter relay solenoid, and replaced a few wired that weren't conducting any electricity. Still no power to lights or other systems, however my door lock actuators are working! I tried to test the current from the starter relay to the starter motor but there is no juice going through that line. My best, albeit limited, guess for now is to start checking fuses...

Or maybe the rest of my fuselinks off of the relay are bad...

UPDATE: All fixed! Essentially had to replace every single fuse link from the starter relay. Starter solenoid had a fried lead so, that needed to be replaced. I even replaced the fuel pump solenoid while I was at it. When everything was said and done I can say that the damage never went past the starter solenoid. When the battery was "not properly installed" it stuck the starter solenoid in the engaged position burning the positive lead completely out of the housing! I was able to get the truck started as a test by manually engaging the starter solenoid AND the fuel pump solenoid together in order to turn over the engine. Cut to now after about $150, and eight hours later, I've completely replaced all of the fuse links, two solenoids, and a new "properly installed" battery. As a bonus, everything else that was wonky with the electrical system in the truck is now fixed as well. A/C blower is now operating as expected, dome lights now come on, the fuel gauge is now accurate, front/rear turn signals...lemme see...oh, cigarette lighter, and window actuators. So, pretty much everything! Phew, sorry for the long post but, this issue has been bothering me for weeks and I finally got everything just right. Thanks for reading!