I must admit to only being familiar with a couple of well-known Led Zeppelin songs (Stairway to Heaven, Whole Lotta Love). I've probably heard others without knowing who they were by.
Looking at the tracks on the album, there was nothing that seemed familiar to me. On the first listen I started, as I always do, by playing the tracks in order of most Spotify plays so I get a feel of which songs are perhaps regarded most highly and then on the second listen played them straight through in album order to see how they all work together.
The first track on the album I heard was therefore Kashmir which started in a very familiar way and I was sure I must have heard it before but when the singing started I didn't recognise it at all. Has some other group used the opening to Kashmir for another song? Anyway I found Kashmir probably the highlight of the album and quite listenable. In My Time of Dying and Custard Pie also both ok. Nothing on disc 2 really stood out.
I have to say that classical rock really isn't my thing at all. Maybe it's an acquired taste that I haven't yet managed to acquire. I know they were an influential band and Bonham, Page and Plant are rated highly as musicians but I just can't make it work for me.
It's probably a fine example of its genre but I just didn't enjoy it as a whole. As such I can't really score it more than 4.