So for a few weeks there I would apply some CLP in the morning before I went to work, and then would gently tap the bolt handle and the op rods when I got home from work. My theory was basically "well hopefully this will work its way into whatever is causing the problem and loosen up the gun." I likely spent far too long doing this, but I figured since I had the time why not. Eventually I took a mallet, sat the gun on it's stock, and gave it a good solid WHACK. The barrel came flying off towards me and the rest of the gun nearly fell over. I'm not 100% certain what happened, but I think the op rod snagged on the barrel. It was pretty fouled under there and and I wonder if that was the culprit. In any event, I was able to take the gun apart, clean it slightly, and then put it back together into good working order. Lesson learned, switching to inertia guns for good.
Thanks for your offer Boof, but given that the gun isn't going to used hard and will likely be sold in the not-too-distant-future, I'm going to treat this as a fluke. None of the surfaces you mentioned appeared worn or damaged.
"So ur afraid to tell ur [Fiance's] dad that u [temporarily jammed] his gun (which you prob [borrowed with his full knowledge and blessing])? Call Mossberg and maybe they'll still hook you up with a free repair if you send them nudes of ur [fiance]."
Uh... thanks for the advice friendo, I'm good.
Pic is related - gun reassembled along with my VZ 24.