6v electrical wizard help needed. (Starter issue)

[NAES]

Helping my buddy on his '58 Westy. Very original with a 6v system and minimal hackery to the wiring.

The problem is the starter not engaging intermittently.

Ignition was removed and sprayed down with contact cleaner. Terminal function verified with a test light and power applied.

Power to the 6v starter relay verified.
Ignition switch power to the relay verified.
Relay clicks when power is applied.
Power verified at starter solenoid when ignition switch is activated.
6v power at the back of starter motor verified.
Screwdriver will jump both starter motor and solenoid to sterter motor. Both sound good with no hesitation.

Battery terminals cleaned.
Battery ground cleaned
Trans strap grounds cleaned
Starter connections cleaned.
Ignition switch screw terminals cleaned.

We're still having an intermittant issue with the switch engaging the starter solenoid. My guess is the starter solenoid is the problem even though it will engage every time with a screwdriver jump.

Are we missing anything? I've exhausted all the things I can think of. Before we swap solenoids or starters is there anything you guys can come up with. I'd hate to have hime throw $130 bucks at the problem with no change.

Thanks everyone, NAES
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