most likely:
Don Rader, Joe Newman, George "Sonny" Cohn, Al Aarons, Fip Ricard (tp)
Henry Coker, Benny Powell, Grover Mitchell, Urbie Green (tb)
Marshal Royal (as,cl)
Frank Wess (ts,as,fl)
Eric Dixon (ts,fl)
Frank Foster (ts)
Charlie Fowlkes (bs)
Count Basie (p)
Freddie Green (g)
Buddy Catlett (b)
Sonny Payne (ds)
by the end of the year -- and maybe already in September? -- Powell and Green had left the trombone section, to be replaced by Bill Hughes and later by Henderson Chambers and Ken Shroyer.