I just read this post/thread. Thank you very much. I had this problem last weekend on my 55 2nd. Smoke under the dash. I pulled the battery wire. Then reached under the dash to find a cooked wire. I have not pulled out the instrument panel but believe it is the wire from the Ammeter to the ignition switch. There is another wire from that same post. I believe it goes from the ignition switch to the light switch for power.
From this thread I realize that the power coming into the ammeter is directly from the starter then runs on to the ignition switch.
This will help me next weekend when I get time to pull all of this apart to see what happened and do damage control.
Thanks again,
