My aircraft had a Brittain AccuFlight II autopilot.That system was completely removed.
The technicians at SteinAir did all the engineering, fabrication, and paperwork.
Yes, there is a 337. I am hesitant to share this for a variety of reasons. Many parts were fabricated in house. To provide a parts list, and have other shops fabricate brackets and such is going to result in variations with installations. There is value in having standardization within a fleet. SteinAir has produced a fine product, it is hard for me to just give it away. One fear is another attempt may result in an unsafe outcome.
This is not say what SteinAir accomplished is perfect, or unlikely to be improved upon. There is always room for improvement. Build a better mousetrap so to speak.
It is very difficult for me to say a GFC-500 install in a Meyers 200 will be exactly, or even about, X dollars. There were unique circumstances to the work I had done. The vacuum system on my plane was removed prior to delivery to the shop. I assisted in the interior removal to allow access to the airframe. Additional Garmin equipment was purchased and installed, package discounts applied and made integration easier. Looking at my invoice, subtracting the GPS, Audio Panel, and GI-275 costs, the rough (wide ballpark) figure is approximately forty-thousand dollars ($40,000). That is a big number. Subsequent installs maybe less (or more?) since the first one is the most time consuming.
SteinAir was a joy to do business with. They may not be the least expensive, but they definitely are among the best of the best.
Hope this helps. Happy to answer any other questions.