1993 Plymouth Laser. 1.8L. Manual.

My sister tells the story that the battery mount slipped loose, the battery slid forward and shorted across one of the hood supports. She turned the key off when she saw the smoke, and then tried to start it again. Toasted the battery naturally. But didn't blow any fuses. Her hubby swapped out the starter solenoid (?) and checked the computer (was all good).
Turns out that in his fuse checks he knocked the prong down on one of the fuse boxes and so it wasn't engaging the fuse. Good deal, right?
Still no go. When the key is turned to "start" I get a humming/buzzing/whirring sound from the starter. My first thought is it's just not engaging...
Thoughts?

P.S. Can provide picture/video/audio if that helps.