Dan had mentioned this to me, and I too noticed this. There are two variations of Hemingray's CD 248 No. 79. The CD 311 sleeves have no variation, are almost exactly the same.

Stacker on the left, the front skirt - .HEMINGRAY. (note dot BEFORE and after 'HEMINGRAY') Rear skirt - № 79 Top 'shed' disc measures 6" width, and is flattened. Note this № 79 sits higher than the other, the distance to the bottom base of the pin hole is longer than the other. It is not because of the CD 311 sleeves.

Stacker on the right, front skirt - HEMINGRAY. Rear skirt - № 79 Top 'shed' disc measures 5½" in width, and is considerably taller than the other variation.

Why are they different? Don't know. Earlier made, different glass plant, or a revised look of functionality? Still don't know... anyone have any input or ideas?