Okay, I was wrong.
Upon close examination it turns out that the loop of fabric that holds my ring in the center of the double handkerchief is attached only to one side of the double handkerchief. This raises the question of how then do the sides not billow out or separate if they are not sewn together in the center.
The answer is because the fabric selected by my wife was a silk/rayon blend that naturally attracts static. Hence, the two sides do not separate. They are held together by static electricity.
Now, for all you history buffs, it turns out that the ring sewn in the corner of the fabric is explained in J. Prevost "Clever and Pleasant Amusements" (or was it "Pleasant and Clever Amuseuments") published in 1584, months before "Discoverie of Witchcraft". (Purchase the Hermetic Press reprint.)
What I find interesting is that the handkerchief was spread out on a table, with the corner holding the ring falling over the edge. Brilliant. It means, of course, that the handkerchief is flat on the table. (No ring in the center.) The ring is borrowed and placed on the center of the fabric on the table and then the corners are brought forward, the ring stolen in the process. The spectator is instructed to hold the ring and the handkerchief.
This is probably the origin of the method of stealing a coin placed on the center of a handkerchief. Same motion, just no duplicate object concealed in the overhanging corner. The important point, of course, was that it was performed originally - at least in this book - from the table. The blocking of the routine in this manner certainly makes a great deal of sense.
I also find this particularly interesting because years ago when I first started performing the Charles Bertram Cups and Balls from "The Modern Conjuror", and did not have pochettes in my trousers, I used to drape a small table cloth over my table. The table cloth had extra balls hidden in the hem hanging over the rear of the table.
Everything comes full circle.