Now I am always happy to be proven wrong, but I was under the impression that all of the small JD's were built elsewhere for JD to JD's specs.
The 100 series smells highly of being assembled by AYP and the small ZTR looks very much like it came out of the same factory as the Craftsman,& McCulloch, with the only difference being the fitting of the "edge" decks.
The mainframe of all the 100 series D, L, LA have all the same redundant holes in the side as every Husqvarna , McCulloch , Rally , Roper, Poulan etc,etc,etc.