Western didn't star crimp the Super-X loads until right about 1948. As I said, your box has RECORD between the upper arms of the X on the face of the box, but I don't see that it mentions Super Seal Crimp on your box?!? My pre-WW-II box is roll-crimped with 4L on the top wad. P37 is the Load No. for a 12-gauge Super-X 1 3/8 ounce load in a 3-inch RECORD shell with 4 being the shot size and L for Lubaloy. Pre WW-II they used a C for chilled shot, S for single ball, and B for buckshot loads as well. After the War they no longer used the C, but still used the B and the L.
For RWTF, when Winchester introduced their Model 12 Heavy Duck for the 12-gauge 3-inch shell in 1935, Winchester/Western introduced the Super-Speed/Shper-X 12-gauge 3-inch Magnum shell with 1 5/8 ounces of shot to go with the new gun. That is about 34 more #4s in the load.