Speaking of Led Zeppelin: Avoid the LP reissues Jimmy Page did recently; in this case the source WAS digital. Also The 2010 (I think it was) Beatles stereo boxset used digitized sources. The mono boxset was originally set to be released in 2012, but the blow back EMI received for going digital---which they were also going to do for the mono box---forced them to reconsider that decision. Part of that was due directly to Michael Fremer, who talked to the principles involved, and set them straight.
All the high end LP reissue labels are analog purists, and in some cases analog fanatics. Before starting Analogue Productions, Chad Kassem was a rare/collectible LP dealer, and he really knows his stuff. Michael Hobson and Ying Tan started Classic Records in the early-90’s, and before that Ying was himself a rare records dealer, working out his apartment just around the corner from the Capitol Records building in Hollywood. You shoulda seen his apartment! Stuffed to the gills with LP’s, every square inch. I got some great old LP’s from Ting, who is a swell fella.
Chad Kassem bought all the rights to the Classic Records catalog when Hobson shut down the label, and his Analogue Productions LP’s are the highest quality records I own. When he set about reissuing the Miles Davis Kind Of Blue recently, he used the lacquer Bernie Grundman cut for Classic Records in the mid-90’s, That lacquer was made from the original 3-track analog multi-track, and rather than mixing the three tracks down to two and making a new 2-track "working" master tape, he sent the 2-track mix straight to the cutter head, avoiding the extra step and tape generation. There are comparisons between an original "2-eye" Columbia pressing of the album, the Classic Records mid-90’s reissue, a contemporary Columbia (Sony) pressing, and the new Analogue Production version. A search on YouTube will lead you to them.
One consideration in choosing between an original pressing and a modern reissue is price. An audiophile reissue---even the most expensive ($125, if you ignore the very limited edition LP’s of The Electric Recording Company, who presses only 100-300 copies of every release, mastered on an all-tube system!)---can be far cheaper than the price of a Mint Condition original, which in some instances runs into four figures. Luckily the titles I am looking for are not amongst those rarities! The price of MoFi, Analogue Productions, Speakers Corner, Intervention, etc., LP’s is currently about $45 per disc.
And we haven’t mentioned the "hot stamper" LP’s offered by Better Records ;-) I also visited the Sherman Oaks, California apartment (located two blocks away from mine) of the owner in the early-90's. Got a copy of the German pressing of Magical Mystery Tour from him, and at a reasonable price.