Look what I just got! An early Christmas present from fellow member 69JL8 who collects old Delco stuff. My wife bought it for me for Christmas, (though she doesn't know it yet). It's an original Delco Freedom II display model (no internal plates).
While it is not year correct for the SD it would be for Gramma's '75. I have seen some of the factory stock appearing racers remove the bottoms and install a motorcycle-sized AGM battery inside and run them as a "decoy" battery.