I made a hand style shifter that fits 50cc Kuzuma and similar ATVs. My little sister had a hard time down shifting her ATV with her foot as the shift pattern requires you to pull upwards for lower gears. This solved this issue for her and I made two when I did this. Made from stainless steel, all hardware needed for installation included. Requires drilling two holes for the bolts. Also still allows full use of foot shifter.
No shifter ball/handle: $15
With shifter ball/handle: $35