I can't see the wiring in enough detail to figure out what was done.
This assumes that the speakers are original 32 ohms each. There are two ways to wire an 810 with jacks.
The first is to wire the speakers in parallel, that is, all the [+] together and all the speaker [-] together. Then the speaker [+] connects to the jack tip, the speaker [-] connects to the jack sleeve (ground). If a second jack is present, the two jacks are connected in parallel for daisy chaining.
The second approach is to be what you seem to have. The top four speakers are connected in parallel, connect the speaker [+], connect the speaker [-]. Same is done with the bottom four but the top and bottom are kept separate. This gives you four wires comming off, a pair each from the top four speakers and a pair from the bottom four speakers. This wiring is show below and the four wires can be seen in your image.
The wiring on the jack plate connects the top four speakers (8 ohms) and the bottom four speakers (8 ohms) in parallel, to provide a total of four ohms. The two jacks are wired in parallel so that daisy chaining can be done. But I can't verify if this is what was done from your images.
Some 810 revisions used a shunt on the jack to switch connections so that the top four speakers can come out one jack at 8 ohms; the bottom four speakers out another jack at 8 ohms. A third jack is often used to switch the cab to mono when a plug is inserted, all eight speakers are connected in parallel for a total of 4 ohms.
My concern is that the cloth covered wires in your image are not what I've seen before. This makes me wonder if your cab has been rewired in some way. I'd want to pull the speakers and draw a diagram of the wiring, also verify that the soeakers are 32 ohms each. A concern is that when doing this there is always a concern that you could put a screw driver through the speaker cone.
