Not the first great old First Aid box I've come across, but definitely one of my favorites, and with this terrific hand-painted lettering over old gray paint seeming to have covered some even earlier, very crudely carved lettering which definitely spells out PLANES and I believe AMERICA below that, and the name Jim Kelley at lower left with planes again and USA. Plus some other letters it's a bit hard to decipher. I'd guess this one saw wartime, but happily made it home.
9 13/16” x 6 1/2” x 2 9/16”, much wear, great patina, structural sound, with a latch on the front that closes.