Glad whatever I was able to contribute was of some assistance to you.
Now, as I'm looking at your photos, I'm just letting my mind coast along a bit as to what kind of overall plan you want to craft on this.
If it was something that belonged to me, I would definitely put a ball-glide on each side of that panel, to reduce your lifting load, and to stabilize the side-to-side position of the panel as it travels.
I'd add a clevis bracket on the top center of that sliding panel (behind the brass lift hardware) and mount your linear actuator in the center of that stationary vertical surface below the TV screen. Some sort of mechanical linkage (which I haven't puit too much thought into) which would allow for a panic situation disconnect from the top linear actuator clevis would be a feature to include out of prudence.
I'm thinking that you should be able to spring mount the "south end" clevis attachment point so that it's fixed, in the "side-to-side" and "front-to-back" directions (x-axis and z-axis); but free, within limits, to move in the vertical direction (y-axis). If the travel of the panel is blocked by an obstacle (child, cat, somebody's tush) the spring will be vertically compressed, but won't compress under normal lifting condtitions. That vertical displacement can be used to operate a safety switch that will reverse the motor direction to lower the panel if something is in the way.
Alternatively, one could monitor the motor current and, if it exceeds a certain level, the same safety protocol would be implemented.
Things like this are more involved to describe that they are to "just do it." Sorry you don't live on the Left Coast, or I'd send you a guy I know, who could do what I'm thinking about in a few hours time.
Don't get offended, but my mind distills volumes of verbage like this to a couple of iconic phrases, at the oddest times. In scanning through this thread one last time, I had to supress a giggle when I saw:
provide some pictures.
This, on the heels of having just cleaned out my nephew's Internet cache, and ridding it of spyware--again.
::: slapping-self and getting more coffee :::