Tonight I was able to glue down the top piece for the left ankle.
As usual, apply wood glue.
Smear it around, clamp, wait a day or so, and it'll be done.
There's still lots to do with these legs. I need to put the groove around the upper ankle, and I need to deal with the Tape-Ease cylinder for the curved part of the ankle, but I may do some sanding and filling first.