I remember seeing a sales brochure showing a 6 row planter being pushed by a New Idea mule, but never actually saw one in action.  Just not practical enough.  That mule would just be another machine you would have to keep working, along with your regular tractor.  If you have ever been around or worked with New Idea equipment you would not long to use it any more than you had to.  Glad you have your photos.  My Dad was a real inventer also.  Build his own 3 point blade, soil scraper, modified elevators for moving seed corn, put a number of tanks in a barn and the graders to grade seed corn.  Even build one of the first high boys to go through tall corn.