I have both copies, so to make sure I hadn't imagnied the red and white copy quality being better, I played them through again. I agree with you, Gareth that neither pressing is perfect, and there is definitely a lower audio quality on the multi-coloured copy when it hits higer/louder areas.
After reading George's comments on the track widths I put my anorak on, found a ruler, and checked the master numbers in the lead out. Both copies I have are exactly the same at 25mm each, so there's another mystery.
Maybe both red and white and multi-coloured label releases have inferior presses on some copies.
Having said all this and getting beyond the technical imperfections, I also agree with Gareth that it's a perfect Northern record, and definitely worthy of a second time around spin...in moderation...