Well, Jesse told ME that MY Barling was fake (but he was right).
Synopsis on OP. George helped me determine that idiot previous owner likely shot adhesive all over the place, trying to disguise the damage. Physics dictates that glue has sucked into the area between the briar and broken portion of tenon, making for poor cost/benefit ratio of paying for professional repair.
However, I have oodles of free time and many small implements of destruction, so I will casually attempt to file/cut/chisel/drill/chew the old tenon from the stummel over the next month of Sundays, then I will seek professional stem repair and fitment.
Mr. Dibos, please correct me if I have misinterpreted or misrepresented the gist of our PM interaction.
Since the original purchase WAS for science, I will keep you abreast of my victories and defeats in this endeavor.