I picked up the build today after a short break, during which I learned about plate thicknessing.
This afternoon I thicknessed the top to my satisfaction, though it feels a little floppy. I knew that going in, as it's a bargain-basement / "student grade" top that was graded that way because it's not very stiff. I've been considering making this a nylon string, and the floppiness may make that necessary.
Once that was done, I thicknessed the back, and ran into some trouble there. One of the halves had terrible tearout, even though my planes are very sharp; but that was taken care of with aggressive sanding. Thankfully the plate was thick enough for that and it looks fine.
Then I routed a channel for the back strip, and screwed up a few times. The way I held the router moved the micro adjustment wheel and I routed too deep, going all the way through in a couple places. Then my straightedge slipped and the channel edges are suboptimal. I wasn't sure whether to use purfling around the strip, and now I have to.
But it looks better with purfling, so it's all good. And the one spot where the channel is visibly too wide is a good excuse to inlay something pretty and pretend it was on purpose.
Next up: even out the edges and bottom of the back strip channel and glue in the back strip.