OK. End of all speculation. Here is the official correct version.

THE GILLETTE LOOK SHARP MARCH (1953) words & music by Mahlon Merrick

Look sharp, Feel sharp Be sharp!

To look sharp ev'ry time you shave
To feel sharp and be on the ball
Just be sharp use Gillette Blue Blades
For the quickest, slickest shave of all.

Source: "Great Songs Of Madison Avenue"

Thanks to my friend, Ron Tilden, from the Alt. Binaries. Karaoke newsgroup. Ron was also nice enough to sequence the midi-karaoke file of this jingle which is available free of charge if you PM me with your e-mail address.
                                                         SOL