radioman -
At this point I didn't do a permanent fix. I played with the PTO lever, "firmly" seating it in the off position several times (6+). The problem stayed intermitent for several times, but at the end the tractor was starting consistently. I have some temporary physical resrictions due to several eye surgeries so I can't go climbing under it just yet.
Once I feel I made some permanent adjustments/repairs, I'll post them here for reference.