Thought I would post this update here, since my tractor "broke" at the plow day. To refresh, after plowing for an hour or so, I noticed smoke coming from the pulley side of the tractor engine. I had my son take it off to park it, followed him and looked and saw the choke cable had fallen against the positve wire on the starter solenoid, directly under the gas tank and was red hot and smoking. This was extremely frightening because I can't get the gas cap to really seal well on the tank so it comes out under the lid, and when it is really bad, gas will drip off the tank onto the footboard - and the starter solenoid is right there in the middle of all this.
So today I finally took some time to look at the damage and see what I could do to fix it. The choke cable was burned in two, and the wire for the headlights had about 4 inches of melted insulation from being routed with the choke cable. I had to remove the gas tank to get behind the dash to replace the choke cable, so I decided I'd try to fix as much as possible while I was working on it.
I had a spare choke control, so that wasn't much of a problem. However, not wanting the same thing to happen again, I drilled a hole in the edge of the dash tower and routed the choke cable through it, safely away from the starter solenoid.
As for the fuel tank, a few years ago I bought a Tecumseh 10 hp with a plastic fuel tank and ended up removing the fuel tank. I pulled it out, checked it against the existing fuel tank, and it was close to being the same height and width as the old one, it just wasn't as long, being about 3/4 as long as the original. As I said to my boys, "a full tank that doesn't leak is better than a bigger tank that leaks when it's full". So I used some angle iron to replace the original tank mount, then drilled my holes carefully to mount the angle iron on the upright bracket between battery and the fuel tank. Clearance was very tight with regards to the hood, and the tank does not rest flat on the support plate the old tank rested on. For the hood, I ground off a tab on top of the gas cap that was standing up about 1/4 inch. To provide support on the bottom, I used some JBWeld epoxy steel to make two flat supports between the tank and the old gas tank support plate. Everything looks very solid, so after waiting an hour I put gas in the tank and drove the tractor around some, even dragging my disc through my garden some.