Trying to repair a spare DOA solar generator

I've got a battery pack from a solar generator which never worked, they're LifePO4 cells with a rated capacity of 50AH at 22.4V (1120wh). They look like pouch type cells, the pack has shrink-wrap on the outside, under that is bound in packing tape. It's in a plastic housing with the BMS bolted to one side.
From what I can tell, the battery either has 6 cells, or 8 cells. The balance plug has 8 pins, 0 and 7 are POS and NEG respectively. I think normally a 6 cell would have 7 pins, and an 8 cell would have 9 pins, so I'm confused as to which this is.
When we got the generator, the internal BMS seemed like it didn't 'see' the battery, display showed the battery was 0%, and it refused to allow current into the battery. Since the solar generator was a free review unit that the manufacturer apparently abandoned, it sat around for over a year. I've got it apart and am trying to rehab the battery if possible. The cells all read between .3V and .8V, which I know is terrible. I've got a benchtop PSU that can put current into the cells through the balance leads, and I've gotten cell 1 up to 2.5V and cell 2 up to 2.5V, I'm working my way up. My plan was to get them all above 2.5V and see if the BMS will allow current into the pack through the mains.
The help I need is, has anyone worked with a 22.4V LifePO4 pack with an 8-pin balance plug? Because if the leads go to multiple 3.2V cells, then I'd need to get them over 6V for the BMS to kick in, right?

Okay. Dumb, don't know why I assumed it has to be an even number of cells. It's a 7 cell, they're just really narrow envelopes.
Has anyone been able to get any sort of capacity out of cells that are this far gone? They've got to be really degraded.

I've recycled batteries before and the best advice I can give you is to dump the existing BMS and grab a JBD 7s. Being able to talk to the BMS goes a long way.

Being a 7s battery makes me suspect it should be LiIon and charge to 25.9v full. All you can really do is get it charged gently and do a capacity test. Either way Free Battery > Cheap Battery!

Yup, I agree. My DIY LifePO4 packs that I made for my RV have JBD BMSs and I love it. I think that if the included electronics work, I'll put up with them. The BMS is sort of combined with the MPPT and a BT speaker with guitar amp, they all communicate with ribbon cables. It's super weird. From experimentation, if any of that functionality is disconnected then it all stops working, which blows.
But IF the electronics are toast, I'll grab a BMS and MPPT along with a DIY BT speaker board since 1/3 of this thing is audio equipment, and cobble it back together again as best I can.
Here's a good example of the quality of this when it arrived from the manufacturer, this is on the BMS/MPPT:

The audio section with the amp and other associated speaker stuff is even worse. I figure it was a prototype that went wrong.