Thank you Kegsy - obviously the only one to understand my (what I think is obvious) comment on 45cat!
Let me reiterate - there are two different issues on HBR. The one with larger lettering (and also the demo with larger lettering), pressed on styrene, is the same cut that was released on St Clair and UK Pye International. The HBR issue with thinner, smaller lettering for the title credits, is a completely different, and cleaner recording, and more (IMO) professionally put together than the one on St Clair. This issue was ONLY pressed on solid vinyl, and no demo appears to exist for this issue.
The YouTube clip on the 45cat page shows the smaller lettering vinyl issue and, quite rightly, plays the correct recording - the more clean-cut one.
In contrast, here is the recording used on the larger lettering HBR release and demo, and also released on St Clair and UK Pye International. Note the last verse where the flute sounds more like a falling H-Bomb, which you (thankfully) don't get on the other HBR release. To my ears, this cut is also rather messy and slapdash. Which also makes me believe that the smaller lettering solid vinyl issue is the 2nd issue, especially given that no one's ever seen a demo for it. Maybe the 2nd issue was put out for the Northern scene? Who knows?