Scharf did score MEXICAN HAYRIDE (and wrote "Is It Yes Or Is It No"), but his music from that picture was merely re-worked into later A&C films (as well as other U-I comedies).
At RKO, Scharf also scored TWO TICKETS TO BROADWAY and, in fact, appeared in tuxedo after the RKO logo with baton in hand to begin the Main Title. VERY AUSPICIOUS!! BTW - no 'stache.
I recall him popping up regularly in the 70s. I remember taping his music for one of the moviola series and the TV version of From Here To Eternity too. think I first noticed his name on the original version of Walking Tall with Joe Don Baker playing Buford Pusser.
Walter was very proud of a deal he made with Universal, allowing his music to be re-used in future pictures of the studio's. It was re-used a lot, and Walter got paid nicely for his work. I had told him I enjoyed his music for BUCCANEER'S GIRL, starring Yvonne De Carlo, and he was happily astounded that anyone remembered that film. A very sweet guy.
Manderley is right, as always. The late Richard Valley's commentary track on the DVD of THE ADVENTURES OF SHERLOCK HOLMES identifies Cyril Mockridge's un-credited collaborators as David Raksin, David Buttolph, Robert Russell Bennett and Walter Scharf.
Scharf garnered 10 Oscar nominations during his career for such films as "Hans Christian Andersen" "Funny Girl' "Willy Wonka & the Chocolate Factory" and "The Fighting Seabees".