are shure this is how they are wired??
i opened my 1960a cab and its a litle bit different and i also checked my friend´s old sovteck cab and its also different!!!
By the way celestion v30 on marshall cabs sound fizzy as hell, and i´ve tried on my buddy sovteck cab and it sound a lot less fizzy, even the low end sounds more controled. With the same wiring it sounded so different.
one thing i noticed is that the front part of his cab (wich holds the speaker) is of solid wood and marshall is of some sort of plywood, maybe that´s what made it so different. All the rest looks the same materials.