I had the same problem with a key switch once when it wore out, you had to find the right spot when you turning the key back from the start position or it would die.
Also something to check is the bulkhead connection, since it was most likely apart when the restoration was taking place, moisture could have corroded the connections and may be causing you troubles.
Also something to check is the bulkhead connection, since it was most likely apart when the restoration was taking place, moisture could have corroded the connections and may be causing you troubles.