It ends up that Zaza's base troubles are a bit worse than I had originally estimated. After pulling each of the motors and running them through a few tests, I found that all three drive (translation) motors are bad. Fortunately, the Tech is closed for renovation the entire month of September, so we should be able to get her back up and running by the time the museum re-opens.
During the month-long downtime we should be able to make a few other enhancements like adding cooling and speaker vents in the robot's upper-enclosure, similar to what the newer B21r's have. This should allow us to keep the enclosure doors closed all the time without the potential for overheating. The speaker audio vents should help improve speech intelligibility too.
I recently added support for Sable markup to the voiceServer. There are some quirks, but it's now possible to re-introduce support for the sound effects we used with the original VB-based face application. Use of Sable also alows support for multiple voices and languages, as well as specifying pronunciation and inflection to improve the quality of the speech.