Not wanting to p*ss on your chips fellas, but Alberquerque is popular amongst Popcorn collectors, so unless the different flip is a pretty good track, the earlier release, although rarer, might not be as valuable as the later release due to demand only being from the Northern Scene (though I may well be talking out of my arse as I suspect most Popcorn collectors would be priced out the market by the price tag the flipside commands on the Northern scene)
https://www.youtube.com/watch?v=7h9ktMUyyG8