Thanks everyone for your comments.
Symphony2 is right it is "just a minor inconvenience " but if is not too difficult to improve I would like to do so.
Tiger79 is also right - there is a flange on the port wheel the same as standard and I have added a better photo to show this.
So I'm back to my original idea of raising the control lever. I have added another couple of photos to show how just 6 inches, if possible, might solve the inconvenience.
Other thoughts are whether it is possible to use a different control system ? Possibly something like an outboard engine or motorbike throttle - turn clockwise for forwards and anticlockwise for reverse. Or maybe a new lever could be designed to shorten and extend or possibly even hinged ? Any ideas ? Cheers.