Benjamin Discovery cocking knob

I still shoot my trusty old Disco, but I am having a hard time with the cocking knob. I find that the stock knob is fairly short, and my fingers get sore during long sessions with it. I'd like to find a knob that is more like an old school PB bolt, fairly long with a downward curve to it. As anyone aware of who might be producing custom cocking knobs for the Disco?