It's EASILY heard ONLY if you have this press,
played on a Tech Das Zero w/ Etsuro Gold cartridge.
https://www.discogs.com/release/2241197-Led-Zeppelin-Led-Zeppelin-III
Seriously, at least on my modest rig and period US press it's subtle, but you have to be focused on listening for it-that takes away from the listening experience.
Kinda like hearing hearing the palm of a hand on the back of the guitar neck.
I'm guessing on a generic CD it's buried from the processing?