Hi Joyce,  Regarding your question of just how the composer and
lyricist should be credited, I don't think there is a particular
preferred layout.  I headed to my pile of old sheet music and
came up with quite a variety.  Here are a few examples.

  Underneath the Mellow Moon
  by WENDELL W HALL
  "The Singing Xylophonist"

  The Utah Trail
  Words and Music by
  "BOB" PALMER

  When the Organ Played at Twilight
  Lyric by          Music by
  RAYMOND WALLACE   JIMMY CAMPBELL
                    & REG. CONNELLY

  The Kentuckian Song
  Edited by         Words and Music by
  Wm. Elfeldt       IRVING GORDON

  In a Golden Coach
  Words and Music by
  RONALD JAMIESON

Kind of an eclectic grab from the top of the heap but the only
consistency I have found in this rather small sample is that
composer and lyricist rate upper case.

Take it from there.

Cheers!
Jim Heyworth,
Sechelt, B.C., Canada