I get what you are saying, but the problem is the ratings are suggested to be based on "Surround," "Content" and "Fidelity" with no option to add points because it was an early recording. Using these guidelines, the best I can give this is a 7: Content:3 Fidelity:3 Surround:1. I might bump it up to 8 with the extra point available from the 10 possible, but right now I'm inclined to leave it at 7 since I usually reserve the extra point for extraordinary surround mixes.
Another way to look at it if you want to compare apples to apples, is to compare this to "Love." I think everyone would agree the "Love" surround mix is at least a couple points better than "Sgt. Pepper"; so at best "Sgt. Pepper" is an 8.
Of course this rating system is just a suggestion, but it helps me give more meaningful ratings. I have to force myself to some sort of disciplined rating system so that I don't end up giving everything a 10.
I think a 7 is a very fair rating.