Just to further document things a bit - here are pictures of where I think the problem was.
With everything back running fine, did a little investigating of the bad cable. As previously mentioned, I was suspicious of the end going to the starter. Appeared to be a possible cold solder joint...
Bear with me on this long epistle. 2004 machine with 700 hours.
Saturday before Easter I did a hundred hour service. Had taken the loader off, when done went out to hook it back up. Turned off tractor but was not quite close enough to hook up hoses - went to start it, heard starter solenoid...
I just got a 2003 1445 that seems to be a good machine. In checking it over there is a vent / breather tube next to the transaxle dip stick. It obviously had a hose connected to it, and the parts explosion on JD shows a tube. But I cannot figure out where the other end of the hose goes...