I think we still have to regard Dietz large fills as starting in 1912, although I have speculated that there may have been a few large fills made in 1911, because we know that Embury was doing that, but I don't yet see any way of proving it one way or the other. The 2H tube reinforcing ended in late 1912 or early 1913 but I also know I am missing a version between my last 1912 and my first 1913 because the 1913 has both 3H reinforcing and the Semi-Shouldered bail. If there is one thing that Dietz was consistent about - it was the practice of making detail changes one at a time. So if two Dietz lanterns have two detail changes between them, that means there is another version with only one of the changes. Prior to 1920, it was common for Dietz to make 3 different versions of a lantern in one year. Indeed, I have 3 different No.2 Wizards that were all made in December 1919 at the New York plant.
I have diverted my attention to the Blizzard line this summer because several important versions have surfaced in the last few months. So far I have 14 versions, not counting streamlines, specials or large founts. The Bliz had 6 different founts, 5 different tubes, 4 different lifts, 6 different burners, 4 different bails and 5 different pull rings.
I'd like to see a picture, but it sounds like a solid 1912 lantern. BB