You're right Dave, LP only "The Spice Of Life" double LP.
I've not seen the 45 on e-bay but I assume its the "free sample" picture sleeve which features snippets of several songs from the LP and a few anecdotes/recollections from Gamble and Huff about making the LP. It was released to promote the LP at the time and is a solid centre 45 playing at 33rpm.
Mecury also relesed one of these 45s to promote Jerry Butlers "The Sagitarius Movement" LP
Cheers Paul