I don't know how Kosher it was to do...but I remember helping my Dad rob the wheel rings off of a junker on the farm and put one between the duals. He said it was to add width to keep them from picking up too large of a rock (we had great gravel roads).
I don't see the problem as long as you have a long enough stud to do so. It isn't much, but it may be all you need.
I agree 300% with the folded tube issue. That and tires run with too low of pressure and the tube slips...