motorized / skew
When your motorized dish is pointed due south, the skew is set to zero.
As the motor sweeps the dish east or west, it twists the dish, which applies the correct skew automatically.
Assuming the LNB with single output is a voltage-controlled one (I don't know about ancient hardware), then the receiver automaticallly applies 12 volts for Vertical transponders and 18 volts for Horizontal transponders.
So again, no problem.
Congrats on the Primestar dishes.
We all wish we had some or more, as the case may be.
Likewise, I applauad your choice of receiver.
I'm sure you'll be quite pleased with it.
edit: oops, took me too long to type. Qwert beat me to it.

Also , let us know which Primestar you have (should be a mold number on the back, or give Vert and Horiz measurememts)
There are threads around here for adapting the larger Primestars to the typical USALS motors; mostly they focus on lowering the weight by removing some of the existing mount.