Thanks, Low. I am hardly an expert, and what I do is no secret- I research the various pressings, and listen to them. In the case of Zep, along with a number of other bands from that era, I decided to seek out the best sounding pressings, which meant having quite a few (I never bought the Classic 'roadcase' of Zep at the time, but have a few of the 45 cuts that were released separately, late in the game for Classic). The sonic differences are readily apparent, but different 'flavors' might exist for different people, based on their ears and systems. FWIW, it was John Davis who did the 2014 vinyl releases of LZ 1-III, and is credited as the (re) mastering engineer for Mothership. But Stan Ricker (who did the old MoFi vinyl) is credited as mastering the vinyl release of Mothership. As best I can tell, Ricker worked from the files that Davis created. Appreciate the kind words.
regards,
Bill Hart