Experienced authenticator Phil Wood has said everything there is to say about this Wilson cap—and said it well. "After 62 years of wearing a cap with either no logo at all or a variation on a block 'W,'" writes Wood, "the Washington Senators in 1963 unveiled a new cap with a script logo to accompany their new uniforms with 'Senators' in script. When baseball returned in 2005, the new Washington Nationals went with the same design, and have stayed with it. Many fans seem to think the 'curly W' was appropriated from Walgreen's Drug Stores, but research indicates that Walgreen's didn't begin using their variation until 1964, so the ballclub used it first."
On the technical side of things, Wood adds, "Inked on the underside of the bill is a faded #15, indicating player Bob Saverine. If you turn the sweatband inside out you'll find a small size 7 1/8 size tag and a long faded cap date code beginning with a 'K' indicating 1967...Unique to the 1963-67 Washington caps is red piping down the cap seams, other than the center front seam. This cap displays significant wear, but is otherwise in very good condition. There is no moth damage and the bill is uncracked and fairly supple."
Wood aptly concludes, "This cap is unquestionably authentic, and while the Washington teams that wore this style 1963-67 never won more games than they lost, at least they looked good doing it."
LOA from Phil Wood.