Just a short update. I had an S2R800 in today for service and had the forks apart. While they looked identical to the Marzocchi ones, I noticed that the markings in the inside of the lowers were different. On closer comparison, it's the brand part that is different, everything else is identical. I have no idea who makes them, but it is a symbol I see on a lot of these late model forks. Photos below show them, Marzocchi with 'M' cast logo on left.
I did notice that the RH leg, which is the one I had played with previously, had rebound damping and no compression. But the LH leg had compression damping and no rebound. A little for most of the travel, a lot more in the last 30mm or so. So as a combination they provide both, and that way you can tailor them as desired individually with different oil weights for example.
I added 15mm more preload, using pieces cut from an original spacer. I'm not sure 15mm is enough now that I think about it, given it had nearly 55mm of sag before we started. But we'll see. I also dropped the oil level to 135mm.