Gents,
You may want to try
www.lefeverforum.informe.com and post your questions and pics there as a number of Lefever afficionados are found there way more qualified than me. The I grade is really the same as the DS grade or Durston Special (which is different than a D grade). The DS grade was available in 12, 16 or 20 ga and available with ejectors as well. The I grade was SUPPOSSED to be available in 12 ga only and without ejectors. However, I "think" I remember one in 16 ga and had heard of 1 or 2 in 12 ga having ejectors. Neither the DS or I grade had anything but steel barrels, no dolls head extension or cocking indicators. However in gun collecting, one learns never to say never.
Jack Kuzepski