Thanks for the advice, all. I've stopped playing with the damned thing and it's now loaded back up with Velvia ready to go. Everything works as it should except for the problem I mentioned (and yes, I do know the difference between the DOF button and the mechanical shutter release lever).

I'll probably get it overhauled when finances allow, as it was essentially unused when it came to me--it's a beautiful late model, the paint is pristine, and the original foam is even still good.

Right now I'm saving up for a replacement F2 body; I sold mine for parts to Sover after the shutter was destroyed in a bizarre accident.