I can't tell from the tiny picture (and single view) what you've got.
But, there are STAB models (the 120 comes to mind), with an up-pointing shaft.
Would that do it?
What we've done many times in the past, is to remove the original heavy mount from fixed commercial dishes,...
... and fabricate a lighter weight (and mechanically convenient) bracket to grab the motor.
The molded ribs on the back side of your dish give me serious encouragement that it would be worth motorizing.
More pix, post the size, etc...