20c Bull (20cLC) first and second watermark

This stamp is much more complicated than I imagined. Now that I have looked at a reasonable number of these, I find the following printings:

Medium color, first watermark, 1E3, flat paper, from 1942, vertical watermark in both directions





Medium color, second watermark diffuse, 2D, white flat paper, from 1943?, horizontal watermark





Another one on thicker paper, poorly perfed





Vivid colors, second watermark-straigh rays, 2C, white rough paper, 1949, horizontal





Vivid colors, second watermark-straigh rays, 2C, white rough paper, 1949, vertical





Dark colors, first watermark on the first late paper, 1L1, from 1951, vertical in both directions





Dark colors, first watermark on the first late paper, 1L1, from 1951, vertical in both directions, worn printing





Light colors, looks like straight rays, but is first watermark on the first late paper, 1L1, from 1951, vertical in both directions





Here are links to additional specimens-I doubt I got all the varieties.

first page of 1E specimens

second page of 1E specimens

third page of 1E specimens

first page of 2C/2D specimens

second page of 2C/2D specimens