Hi Russ,
Thanks, I've never been referred to as an evergreen classic before!
Yes, apart from the original US RCA 45 (RARE on a stocker), there is indeed a unreleased RCA LP in circulation which features an alternative version, which has a fantastic additional trumpet break and additional chorus. It is not an acetate, it is vinyl, it has no picture cover and it came with the engineer's original notes too. As already stated it was turned up by Benji in Germany from a sound engineer in Cologne.
Yes, Greg used to play it at the Capitol Soul Club, and it used to surprise a few tired legs on the dancefloor as the the realisation of it being a longer version hit home!
d.