Very interesting Remington Parker marking.
I don't know of any North American ammunition manufacturer offering anything but 2 1/2 inch and 2 7/8 inch 28-gauge paper shells. Just before WW-II the 28-gauge skeet loads began being put up in 2 3/4 inch cases which became the "standard" for 28-gauge shells not long after WW-II. The old roll-crimped 2 7/8 inch paper 28-gauge shells look really long and I've known of folks thinking they were 3-inch.
Here is a smattering of pre-WW-II 28-gauge roll crimped shells and a roll-crimped 20-gauge 3-inch Magnum Peters High Velocity for comparison.
From left -- Shurshot 2 1/2 inch shell, loaded length 2.357" -- Nitro Club 2 7/8 inch shells, loaded length 2.724" -- Remington Express 2 7/8 inch shell, loaded length 2.686" -- Western Super-X 2 3/4 inch shell, loaded length 2.586". The Express has a deeper crimp than the Nitro Clubs.
Same first four shells with a 2 3/4 inch Shurshot roll crimped shell added at left end --
Loaded length 2.562".
And finally, here is the 2 3/4 inch roll-crimped Western Super-X from the first picture with a loaded length of 2.586" with a 2 7/8 inch Super-X roll-crimped shell with a loaded length of 2.680".
The 12-, 16- and 20-gauge paper shells were offered in a greater variety of lengths.