If your plan is to measure the frame and create plans or your own frame based on those measurements, and you are getting the chassis cheap enough to make that worth it, I say that is a great idea. I'd personally love to do that.
If you plan to use this particular chassis in a car, forget it! The metal is definitely weakened by the fire. Look at the firewall area (likely the hottest point of the fire). The metal is melted / eaten away - it is gone. If you look at the frame that supports that area, you can see damage they couldn't sand blast away or paint over. This is just the visible damage. I guarantee, there is damage there you can't see too. You can tell form the pre-painted pic that that fire burned all the way to the front of the car which means in the back where it likely started, it burned hot and long. Not good.
I don't know what the going rate for a frame in this condition is but I believe John Watson still has a burned out frame. I believe Victor (Dr. Murcielago) in the U.S. may have one too. You may want to contact them to see what they are asking before you take the plunge.
