Are these versions original 1976/1979 mixes?

[Pierre Declercq]

In some compilations, we can find special mixes of well-known songs. Do somebody knows the story about each one of the five listed here? Are they original mixes from the vaults or new ones specially done for the compilation? [We had a thread in the same style about Jimmy Ruffin’s «Tell me what you want».]

THE DISCO YEARS Volume 4 : Lost in music (Rhino)1992
«Hot stuff» by Donna Summer, an edit [4:20] with unreleased ad-libs;

Four extended versions longer than the original 12’’ version:

DISCO SPECTRUM Volume 3 (BBE) 2002
«Heartache no 9» by Delegation [6:50]

DISCO FANTASY (Ace records) 1999
«Gotta keep moving» by Martha Reeves [7:50]

FUNKOLOGY Volume 3, Dance divas (Motown) 1996
«I’m gonna let my heart do the walking» by The Supremes [4:10]
same version on the 2000 compilation «The Supremes»

LET’S START THE DANCE Volume 2 (PolyGram) 1989
«Walk away» by Donna Summer [8:30]
same version on an Unidisc 12’’ (b/w «No more tears»).

[Westwood]

Well as far as The Supremes go, they seem they will always come up with slightly alternate versions to keep us interested, to make us happy and.....to pick our pockets lol.
Motown seems to have loads or alternate takes and mixes and they are not shy to share them with us. I haven't seen similar doing in other labels/artists I know.

[Pierre Declercq]

Thank you Westwood but this mix of the Supremes is just a re-edit and not a real alternate take.

[Disco Funk]

I just looked up Heartache No 9 in the vault, and it says there's a 12" that was released in 1980 with a special remix of a similar running time.

Disco Funk

[Pierre Declercq]

Oops, didn't know that
Delegation - Heartache No. 9
Delegation Heartache #9 (12") Disco Music.com

The only 12" I knew was the Mercury MK150 (US) with the lp version:
Delegation Heartache Nr. 9 (12") Disco Music.com

But the other songs? Donna Summer?