Gama has a CDK 20" from Planewave on a MI-750 mount.
Though I am not certain a CDK is exactly a good fit for a Visual scope, its full potential would be under used.
http://www.iceinspace.com.au/forum/s...&highlight=CDK
Another Alternative is as some one else mentioned maybe an RCOS EQ Fork, which has a relatively small foot print.
http://www.rcopticalsystems.com/moun...quatorial.html
I still recall my school visit to the Observatory and the Meade scope, I hope there is some way to keep it going. Maybe place it another Observatory in NSW. Or perhaps you could just defork the OTA and get a new Mount for it.