I also notice in Father's Day there is an overlay on Henry Goes Looking and through the 30 seconds of Mediation. It sounds like ghostly moans but I think that was created for the score and not a library track.
That is most definitely John Harrison. If you listen before Meditation kicks in, it is one of the Grantham family themes being played. The same theme you hear just prior to Nate popping out of his grave.
0:13 THE PROLOGUE 2:10 THE CREEPSHOW WELCOMES YOU 4:24 Andante from Eine Kleine Nachtmusik (Erik Markman) 5:12 HENRY IS TOLD THE FAMILY SECRETS (omits 0:31-0:48/ repeats one bar 0:48-0:50/ unreleased 17 seconds) 6:16 TC-749 Sonar Waves (William Loose) 6:30 SHE BASHED HIS HEAD IN 7:09 TC-749 Sonar Waves (William Loose) 7:28 TC-745 Deep Sea Test (William Loose) 7:39 BEDELIA ARRIVES (omits 0:00-0:27) 8:00 TC-746 Tide Research (William Loose) 8:27 Not Identified 8:57 WHERE'S MY CAKE?/I WANT MY CAKE (film version piano plays through to the end) 10:19 TC-748 Undersea World (William Loose) 11:28 TC-745 Deep Sea Test (William Loose) 11:56 NATE COMES OUT OF THE GRAVE 13:01 Don't Let Go 13:52 HENRY GOES LOOKING (overlay unreleased) 15:03 DM-224 Meditation (Erik Markman) 15:37 TC-74 Somber 2 (William Loose & John Seely) 16:34 HENRY MEETS NATE AND GETS CRUSHED 17:37 Don't Let Go 18:30 I'VE GOT MY CAKE (0:00-0:24) 18:41 TC-73 Mysterioso 3 (William Loose & John Seely) 19:04 I'VE GOT MY CAKE (0:24-0:52) 19:30 TC-223 Suspense 2 (William Loose & John Seely) 20:41 SLYVIA ON A PLATTER/ A METEOR ARRIVES (Missing the first second ) 21:20 Mysterioso 6 (Philip Green) Overlay unreleased 22:23 Heavenly Harp (William Loose & John Seely) 22:26 Graduation Day (Erik Markman) 23:01 Heavenly Harp (William Loose & John Seely) 23:18 Spy Fingers (Ib Glindermann) 24:00 Heavenly Harp (William Loose & John Seely) 24:01 JORDY AND THE METEOR 24:16 Heavenly Harp (William Loose & John Seely) 24:22 Spy Fingers (Ib Glindermann) 24:32 Exotic Movement (George Hormel) 24:44 Spy Fingers (Ib Glindermann) 25:46 Danger Tension (Ib Glindermann) 25:47 Sonar Waves (William Loose) 26:11 Not Identified 26:16 Exotic Movement (George Hormel) 26:32 HENRY IS TOLD THE FAMILY SECRETS 26:37 Heavenly Harp (William Loose & John Seely) 26:41 Not Identified 26:45 Shock 1 (Ib Glindermann) 26:48 HENRY IS TOLD THE FAMILY SECRETS 26:57 Light Chase (Phillip Green) 27:38 Mysterioso 6 (Phillip Green) 28:03 Overlay (Unreleased) 28:20 Eerie (Phillip Green) 29:44 Unreleased 29:56 Spy Fingers (Ib Glindermann) 30:26 Freedom Flight (Jan Kennedy)