could it be the battery ? unit is from 2004 and I do not know if the battery was ever changed
Yikes... You may want to replace the battery for starters. Proto-2 engines will not leave neutral in conventional with a weak battery so if you're running conventional the battery may have been replaced at one time.
In command the engine will still operate with a dead battery. (you just can't change any settings and the engine will drop into neutral at the slightest power interruption).