A subject near and dear to my heart. My comments are based on my ownership of a number of used Grade 1 models.
As a retired "working man', I have found this model very attractive and within financial reach. I tart up nearly all of my shotguns with a recoil pad for increased LOP, and the BIG Bradley white front sight, often with Lyman white mid bead. It works for me.
I hungered for a Superposed as a young married man in the 1960s, and a number eventually came my way. Actually using these Supers gave me the same rush and inner warmth as riding my 1955 Matchless 500 single. It was a heart and headbone thing. The Super and Matchless were machine made industrial products, both being somewhat dated designs with a heavy dollop of period craftmanship.
Too bad Neds Schwin'g Superposed book is a bit shallow technically, focusing rather on engraving, flashy versions, and charts. Painfully obvious that some of Schwing's pictured higher grades examples have grotesque charicatures of birds and animals, not quite "flying turnips' but close. Page 94 shows an interesting picture of the 1948 Christmas dinner at the Browning St.Louis plant - with the diners sitting on bundled up cardboard gun shipping boxes.
My South Carolina mentor observed that the Superposed soon faded from the hands of serious southeastern US skeet competitors because it was too light, and because the forearm was too difficult to remove to clean and dry after the frequent afternoon downpours.
My double dated 1948/1949 12GA, 30" Super, with the stamped "CANADA" mark under the lower chamber, and my 1951 Trap, are my favourites. The 1948/49 Super was seriously overchoked, until I molested/opened both chokes (from the muzzle end) to Imp Cyl and Full, and is now simply a RADAR Gun in my hands.
These Grade 1 Superposeds are a lot of value for the money, and very useful when the barrels are modified (opened up) for modern one-piece wad ammunition.
All comments/opinions apply to my Grade 1 guns and are offered FWIW.