That's a DARN good idea Robert!! (your dome) This subject is one of my favorites! (CHEAP astro-gadgets!) How about a RA motor drive for a 12.5" newt/EQ for under 50 bucks or making a 6V battery by cutting a 12V in half with me trusty hack-saw?...Or perhaps a manual fine focuser.
I've thought of the observatory made outa paper mache many many times, lol.