With the wood glue dry, I puttied the gaps around the ankle pieces and the edges of the outer legs. I went a little overboard, but I figured I could sand everything down at once.
I used a RotoZip with a Dremel bit to route out the outer ankle channel detail. I set the depth and routed out the majority of the channel. I then came back and used a razor blade to clean out the corner to make 90 degree angles. I then used a chop saw to cut down the outer ankle pieces to 4.1" and glued the ankle pieces to the legs.
After the wood putty was dry, I sanded the ankle pieces smooth and painted them. I looks like they will need some more wood putty and need to be painted again later, but I can do that after I glue them to the legs.
With the new angles cut on the ankle pieces, 6-year-old Joshua helped me trace the new end caps on some flat 1/4" plywood. He loves it anytime he can help! I cut them out and re-glued them.