Eventually managed to find vol1 and vol2 of the Marriott's Detroit tapes.
Vol2 is missing the original inlay, just a typed tracklisting, here it is:
Connie Van Dyke - Don't do nothing I wouldn't do
The Metros - Since I found my baby
The Lollipops - Loving good feeling
Arabians - Please take a chance on me
Bob & Fred - I'll be on my way
Martha Starr - I'm lonely
Jimmy Ruffin - Don't feel sorry for me
Four Gents - Young girls beware
George Freeman - Down and out
Sea Shells - Quiet home
Appreciations - It's better to cry
Soulettes - Bring your fine self home
Four Voices - Your love is getting stronger
Gwen Owens - I lost a good thing
Magnetics - Heart you're made of stone
Jackie Beavers - Love that never grows cold
Steve Mancha - Did my baby call
Gwen Owens - Mystery man
Diane Lewis - you ain't got a chance
Lee Rogers - Sock some love power to me
Lorraine Chandler - Tell me you're mine
Emanuel Laskey - Don't lead me on
Rose Batiste - I just can't leave you
Melvin Davis - I must love you
Debonaires - Loving you takes all of my time
Doni Burdick - Bari track
I know some mistakes among them, i.e. George Freeman and Diane Lewis C/up aren't Detroit. But great stuff nevertheless
Here's a scan of vol1's tracklist: