Ahhh....The Ampeg fridge....I think Jensenman went off on a tangent but I'll try to reel things in..
Sooo...There have been significant changes to the 8x10 cabs over the years. Differences in construction...Differences in speakers used. Assuming that there has been no damage to the speakers in the cab at any time, and nobody decided to change anything along the way, then the cab will have 8 identical speakers in it.
In Jensenman's cab, it sounds like he has an original 8x10 with 4 original speakers and 4 replacement speakers. This could happen for any number of reasons. I've seen pics of 8x10's on the road that have had individual speakers replaced that had been blown. In that case...There would probably be a difference in tone between the original and replacement speakers.