That
Super-X The Long Range Load booklet you picture is much later than 1927. That cover was used from the first one to include the 3 1/2 inch Magnum-10 dated 11-32 on to the last ones in 1935. The earliest
Super-X Loads booklet, from 1922, just has the 2 3/4 inch 12- and 20-gauge loads --

The earliest one of the
Super-X The Long Range Load booklets I've found is not dated and has a grey cover with red and black ink, then a similar one dated 5-28. They both include 10-, 12- (2 3/4 & 3-inch), 16- and 20-gauges and .410-bore Super-X loads. Then in 1930 to early 1932 there are a number of different cover colors --

4-30 left, 2-32 right. The one dated 2-31, the first to include the 28-gauge Super-X load has a beige cover with blue and black ink.
In the first Western Cartridge Co. catalog to include the Super-X they show the 12-gauge being in the FIELD shell and the 20-gauge in the RECORD shell.

I have three of these catalogs and in two of them the 20-gauge page has penciled in that they are in a FIELD shell.
In the Super-Fox brochures when they discuss the Western Super-X loads talk about DuPont 93 and DuPont Deluxe.