I filled in the knotwork with plaster. I did this after I sanded the inlay for the axes flush. I’m putting this here, because when I added it to the #3 entry, it messed up all the pictures that came after it.
MUTE YOUR VOLUME!!! It’s really loud. Or at least it can be.
I'm guessing now that I should have waited to sand down the desktop =AFTER= filling this in. It was another round of 150-180 to get it flush. And that was after taking the hand sander to it to simply knock off the tops. Don't use a power sander to knock off the tops, it'll simply pull the plaster out and ruin your work.