Last year I got this reel and started liking it after some great success. Butt as I mostly use it for targeting large halibut very deep the crank arm and the ball knob seemed like it could use improvement.
Below is the donar arm from my Tiagra 30 that was excess at the moment. A new piece of stainless steel was fitted and tig welded. It's far more comfortable. Here is some pictures. :-\
This arm is very strong and will help me get the last of the line in after the motor is stopped.
The factory arm shown below. ;)
Looks like that should give you plenty of leverage.