Is it worth repairing my vehicle?

My husband has a 1983 Ford Mustang GT 5.0 V-8 convertible suffered an engine fire in our garage when I started it one day. He was in the hospital recovering from 2 strokes so I would warm his car up every 2 weeks or so. On the last occasion, I warmed it up after sitting for about 3 weeks in our covered garage. When I started it, I pressed a little gas and it idled, I looked behind and noticed some black smoke coming out of the exhaust (this happens when the car doesn't run for awhile). Then, I noticed smoke coming out from the front hood (closed) and I got out and looked under the car where there was a small flame (possibly from oil or gas that dripped or leaked). So, I turned off the ignition. But the headlights came on and the fire got bigger.I called my neighbor who jumped over the fence and grabbed my water hose, I popped the hood and he sprayed water on the engine to stop the fire (I didn't know where my husband kept his fire extinguisher). Luckily the fire stopped, and no damage to the garage or house but, my husband's baby (his mustang) was seriously damaged. He is now at home and disabled. He blames me for burning his car which I feel I didn't do. He wants me to see if his car can be saved. What or who should look at it, etc. My neighbor came over the other day and said that will need to replace the wiring harness, don't know what else but, maybe your expertise can be helpful or at least guide me to a specialist who can do such repairs/estimate as needed. :Roll: