Del and Matt, you guys have the same middle name
Except he's graceful and elegant. And I'm, well, Clueless
Update: I'm stuck in the office again, but I decided to give my hinged limb a bit of heat to see what happens (I reckon the bow may be irreparable, so this is all in the name of science).
I used my gas kitchen stove on a low heat, and held the belly about 5" off the flame. It took about 5 minutes, as I only heated the dodgy section of the limb. I couldn't prevent the very edges of the limb starting to blacken, but the rest of the limb is a dark red colour, compared to the usual 'rare roast beef' look of massaranduba.
I'm going to put it back on the tiller later, but my first impression is that the belly seems very much stronger than it was. Im going to lightly sand the burn marks off as well.
My advice is, if you're interested in heating your bow for hardening purposes, make sure to give it lots of cold water to drink during and after. I was shocked at how dry it makes the wood (and I'm used to dry wood. I live in Johannesburg, which has about 25% humidity).