I've had mine since the early 80s & it's version 1, No 3 I don't think I've ever heard before, the vocal is so different !
I don't actually notice any difference with the sax break as mentioned in the discogs listing & not sure that there is any difference re the handclaps.
Mick could be right in that version 1 is a slightly "softer" mix but again as Mick says it could just be the recording level on you tube.
To my ears & they are old & rather battered but it seems to me that the instrumentation, the girls vocals & the handclaps are all the same & I wonder if Lou simply recorded at least one of the versions singing to the already recorded backing track & his vocal is the only difference ?