the bendix is likely hung in the ring gear since you use the starter to motor it off the road. loosent he starter a bit then rockt he back tires while in 4th gear.. then give her a try.
do , however, check ytour electrical connections.. especially ground starp. remember .. both sides.
as for the ei failure.. Ultradog may be along in a while to help, he really likes the ei modules.. otherwise.. time to call tech support and check out the warranty.. or buy a new one. or put your old breaker plate and points back in and be able to use your tractor in the mean time..