Commenting so that I can see responses later. I have setup mesh for a friend in his rather large sized backyard, though I did it in a different manner. His barbecue is at the back of the backyard, adjacent to an outdoor power outlet, and the barbecue has a large cabinet below it. I simply stuck 6 foot outdoor extension cord inside that cupboard, and plugged in a powerline adapter and Asus router. Instant AiMesh with the powerline adapter as the wired backbone. It’s been working perfectly for over a year now.
Can’t tell without a legend as to what pins are mapped to what punchdown. That would likely have come with the jacks when they were purchased. Look at the other end, and then just wire your new wallplate according to that, or trial and error, as you have a 50/50 shot. Just don’t trim your ends until you test it, and leave a touch of extra cable, so you can just pull them out and punch it down the other way.