I'm trying to soften it up and then press down on it so it cools in the proper position.
Success! Or at least, sort of. I carefully pressed the two warped pieces of guitar base together, inserting the screws and going from one side to the other. Getting the last screw in was really hard. Then I cranked down on all of them for a tight fit. I baked it for about 30 min, then removed it and let it cool with some heavy books on top. After it was cool, I removed the books and took the screws out. The two peices are less warped, and all the screw holes line up without any manuvering.
The downside is, the edges don't quite match up. Doh!
So yeah, plastic may not "melt" at 175F, but it softens enough to take on new shapes.
And I baked it to help the paint dry, since the paint was not really drying well earlier.
I'll be sure and post some pix of it when it's done, although it's probably better suited for "noisy rock music PC review" than SPCR... :p