Just like on the left foot, the motor doesn't accommodate the battery box for the right foot, since it rests upon the footshell.
Whee, time to hack the motor. At roughly 2-3mm per minute, this is slow going.
Hack, hack, hack.
Hmm. That was supposed to help more than it did. The battery box still isn't fitting quite flush against the foot shell.
I took a look and it seemed like there could be two or three areas of interference that may need to be addressed. However, I was tired and could see exasperation on the horizon, so I decided to leave that for another day.