Does anyone know if there are engineering drawings of the C-30 available on-line? I am trying to remove the throttle/shift assembly on my 1980 C-30. These are the two levers that are mounted on the port-side cockpit wall and operate the shift and throttle cables. I have the levers removed and the retaining nut that appears to hold the interior assembly to the outer flange. However, I am still unable to remove the outer flange. Engineering drawings would help me to understand how the thing is put together. I can't tell if the outer flange is threaded on to the thruough-wall tube or is just rusted tight.Any suggestions will be greatly appreciated.Bob BollerBenicia, CA