I guess I'm not too concerned about stopping it before it's limit.
Here's an email clip from Craig Colvin who explains what is needed and how to do it. I also spoke with someone at Stewart who said it is very doable:
The X10 module you want to use is called a Universal Module. Here is a link
to a description http://www.hometech.com/modules/modulesb.html#special
You would wire it so that the +12v used to control the Stewart screen goes
thru the contacts on the Universal Module. The Universal Module would be
assigned an X10 address (let's say B1 for example), you would then send a
X10 command B1 ON to lower the screen or B1 OFF to raise the screen. You
would have another Universal Module assigned to address B2 to control the
Electric Mask. The command B2 ON would lower the mask and B2 OFF would raise the mask.
-----end of email
I'll be ordering the modules soon.
As far as the animation on my site, I used Lightwave 3D from http://www.newtek.com
It's a high-end modeling and animation software costing around $2400. They do offer a lower end version entitled Inspire 3D.