The IP switcher looks interesting Fred, I could do with another gadget...
I don't have any expertise with observatory automation but it might be worth considering a regular garage door (panel lift) opener for opening and closing, they work reliably for years on end and have limit switching and adjustable sensors for obstruction inbuilt. From memory they cost less around $500-$700 and both push and pull.
You could use something like a
Zelio smart relay or PLC to handle the opening and closing, house keeping & failsafe, that way you're not compromised if there's a PC failure (provided you can get the mount parked).
I use a Zelio smart relay in my roof space handling some simple functions, they're easily programmable from PC and (depending on the model) run with low voltage supplies, have timers, mutiple relays and analog inputs (e.g. for rain sensor, fail-safe for park detection etc). I notice that they have a GSM equipped model, could be useful if you're not net connected.