I think it is M12 but I will check one tommorow and post
My shifter knob is aluminum, not plastic. I have a RHD-right hand rod shift, not a center shift. You might want to double check the center shifter thread size, it might be 12MM. Sorry about that.
You can have one of these with any thread you'd like :shy:
Double checked two LHD chassis today, thread is 10x1.25 (my tap/die kit has a 10x1.25 tap and a 10x1.50 die...go figure?) Double checked them with a pitch gauge and they both measure at 10x1.25.