The Rare Stamps track (from memory) is a different cut and to my ears a different vocalist, I belive the RS track is infact correctly attributed to JJ Barnes and of course the Hollidays track is Steve Mancha just listen to it it can't be anyone else.
If you can find a Hollidays Groove City 45 at £400 I would recomend you buy it as it is a very hard 45 to locate.
Kind regards
Paul