Pssst! Hey, kid! Wanna see a movie about the history of the wah-wah pedal?
Not sure, but I think Eddie Kramer might be wrong about having heard Jimi use one in London in '66. While he may have had one then, I'm pretty sure his first use of it on record was "Little Miss Lover" on Axis: Bold As Love; I don't believe there's any on Are You Experienced? -- could be wrong. For me, the big wah-wah records were Jeff Beck's Truth, the first Led Zep album (although Page used one liberally with the Yardbirds, nobody ever bought the records they released with him until later), and the first Stooges album.
I got my first one from the guys in the soul band I played with in high school: a Uniwah by Univox, which was made by a company called Merson on Long Island. You couldn't lock it in position like a Crybaby/Vox, so I used to roll up a handkerchief and stick it under the foot pedal to get a fat midrange boost. Can't remember what I wound up doing with that pedal.