Hi Larry, Benzmac and Q,
Thanks for the feedback.
I tend to think that the culprit is not the starter itself, but rather the circuit that triggers the solenoid. This is probably due to increased resistance within the circuit caused by natural decay of the wires, a process exarcebated by 22 years exposure to our eternal summer climate. Hence, all you need is some serious driving in 95 degree weather to trigger the circuit failure.
A couple of members suggested off-Forum that I should run a separate circuit from a 12 volt source (either battery or switched)and mount a "momentary" switch under the dash.
Is this practical and what is the procedure to set-up this bypass connection?