FWIW I took a chance and ordered some from target Sports USA and when they arrived they were indeed 12ga 3.5" 2-1/8oz #5 shells.
I checked and they are still in stock but the picture and add say 2-1/8oz #5 but the description says 2oz #5's.
So if anyone is interested in buying some I suggest calling TS USA to confirm they are indeed 2-1/8oz shells.