Ed
I think its one of those things you only built once, and do a ROR next time, its not a trivial task.
The dome will sit on a 1m odd high round pedestal (with an access hatch).
The driving, well thats a head spin. The last resort will be a 3D printed circular rack and pinion in sections but thats a monster print job, so im thinking of other rack like things like timing belt or chain stuck to the side, even bolts every 20cm or so as "teeth".
The latest learned thing (bit obvious really) is the waste in cut offs, some 30%. Round is a bietch.