Thanks for the help so far. The grounding strap from the bellhousing is definitely on there good and tight and corrosion-free. I had not thought about adding and extra grounding strap directly the to starter. That might be my next move. I am definitely thinking the horn is not related. I recall having an issue with it before the banishment of the poor car for her rebuild, so I don't think it is related. The tach, for this morning at least, cooperated after I replaced the fuse in the OVP. I will have to wait and see if it continues to behave.

Glenn