Here is an example of a significant profile variation with the CD 104 New England Tel & Tel insulator. This does not qualify for a new variant number, i.e. CD 104.X in accordance with the Consolidated Design Guidelines. Per request from various members:

The taller more common variant green on the left measures 2-3/8 inches base rim diameter X 3-7/8 inches tall. It is also embossed with a backwards 7 on the dome top.

The shorter scarcer variant blue on the right measures 2-3/4 inches base rim diameter X 3-1/2 inches tall. Embossing on skirt ~ NEW ENG TEL & TEL CO There are no periods and the N's in NEW and ENG are backwards. No dome mold number or any other embossing on this example.

NOTE: the sharp edges that form a more symmetrical semi-circular wire groove. One other short wide variant for which I am familiar exhibits a much more rounded wire groove edge.