I have seen 492 G11 heads offered for as low as $750 recently. MA adapters are $100-125 used, but they don't come along often. If you can find one this Losmandy made adapter for the G9 will work for a Celestron field tripod. OnStep goto offers a inexpensive alternative to to Gemini II. See my blog for information.
I had a couple and let them go for $40. It would be fairly easy to machine. The center six holes can be omitted as they were for bolting it to a CG-5 tripod hub. The outer holes are located to use three of the six wedge fastening holes and two for the mount fastening holes. A 6" by .05" slice of aluminum rod runs about $20 on eBay.
On early tripods the six wedge holes were threaded 5/16th". Later hubs have three threaded and three unthreaded. In the photo of the adapter mounted you can see a 5/16th" bolt under the hub used to fasten the adapter.
George
https://www.stmbluepillkits.com/
