I've had this Maestro for about 4 years. I can see that I may have to replace the tablet with a new. What if the model A tablets are no longer available is this Maestro toast.
Since you have it opened you might want to try some experimenting. How about running a extension for USB and then add mouse control? What about an extension to add external HDMI and a larger monitor. Maybe some other creative things that the tablet can do on it's own but is restricted once installed in the Maestro.