Rotary dial "buttonbox" for Accuforce v2?

[dud]

I have an Accuforce v2 with their default steering wheel, and their own button box. The box only has straight buttons. I would like to have some rotary and "left-right" switch.

What are my options?

• Entirely different buttonbox? Would that re-use their cable and how much would I have to change in the software? How is it ensured a different box fits the steering wheel?
• Some add-on, keeping the existing buttonbox? Any options? How does the cabling work? I assume I wouldn't be able to use the existing telephone plug?

This is what it looks like by default: