Thanks JamesStein. I'm thinking my problem is a worn ignition switch, because my key/tumbler inserts/removes/turns 100% fine. So I think after 21 years and 205K miles the electrical contacts have worn enough that they don't make good contact on occasion (like a worn distributor cap on an old gasser. If I'm going to drop the dash/steering, I might as well replace the switch and vacuum line switch on the lock assembly (at about $30 for each they're cheap enough) - I only want to get under there once. Does anyone think these could NOT be the source of the problem?