Like most bands, the Pistols influences were diverse and varied from member to member.... Johnny even liked Van Der Graaf Generator (though I can't hear it in the songs!) and Matlock was a Small Faces fan, and of course they were all into the Stooges...
Glam was certainly a major influence... as someone said earlier, just listen to Steve's guitar, but I doubt if the Pistols had heard much about the Ramones prior to the "Bi-Centennial Bop" (or whatever it was called) at the Roundhouse... it was a great show (I recall the Ramones manager shepherding them side-stage to watch the brilliant Flamin' Groovies and pointing things out to them energetically.... it looked most humorous... as had the Ramones running onto stage earlier, going "1-2-3-4" then.... nothing! The amps weren't on... and after some techies ran around feverishly, they came back out and did it again... but this time they ROARED!!!!), and yes nearly everyone who was into what would become "punk" was there, but an influence? The New York Dolls certainly... A friend and I accidentally saw them in 1975 and it was a Dolls-sounding song that made us look up from the bar (it was not until several years later that I realized that we had indeed witnessed an early Pistols show at our local pub! DOH!)
So I definitely vote "Glam" !!
Cheers, Peter Brat