Intermittent starting problems

Have you investigated the neutral safety / clutch switch? You could temporarily bypass that by grounding that pin of the starter relay. It is the wire that head off from the relay (dark colored) down the fireway to the auto, or through a separate grommet into the firewall (clutch) CAUTION will now start in any gear!!!

Before you do that have you tried holding key in start, and wiggling auto shift lever, or working clutch up/ down with gearbox in neutral?