I would guess the reason behind the Magnetics rarity was it would appear there was a bit of a pressing problem on some of the copies.
When I got my copy the chap I purchased it from had got 2 copies. He already had one copy & had just managed to get Dennis Coffey's file copy that he'd kept since his input on the recording. The copy from Dennis, although in lovely visual condition, had some sound distortion. Not hiss or pops, but that sound distortion you get on some records where there was a pressing plant mess up. I listened to the copy that JM just auctioned & think I can hear it on that one. Anyway, I grabbed the one that played perfect. I was told the bootlegs were done from a tape of this copy (prior to me owning it). Since then I heard a tape recording of another copy & that had the sound distortion.
It's weird how you can have a pressing run where some copies play perfect & some don't. That's the same problem on Gwen Owens -"Wanted & needed" on the 'loud press' where most copies jump. Most of the loud copies distort, but I did hear one copy that sounded pretty good.
Re Mr Chadwicks 2 copies. Real copy & a boot to play out ? His had really bad needle hiss on the Lady in green side. That copy went via John Anderson to Hertfordshire.