The off road big bore Honda levers have the same spline as the F650. The CRF450 lever is the closest to the shape of the F650 lever and around the length needed for full relocation. These levers are available cheaply and can include a folding tip.
A gear lever diagram with detailed information on bending, drilling and gear lever tips is available below in PDF file format for those who need to bend or modify a gear lever.
The existing lever can also be simply modified as per the information below, The existing tip can either be retained or cut off once you have determined the best length for you
1/ Remove Lever from machine
2/ Mark and drill Lever as per image
3/ Re fit Gear Lever
4/ Fit Gear Lever Tip
See lever tip alternatives below
Cut Folding tip from an aftermarket lever
Disassemble, drill and tap 2 5mm holes as per drilling template
Simple or Emergency Tip
Obtain 50mm length of 15mm diameter solid alloy or plastic rod
Drill 30 mm deep 5mm dia hole in one end. Tap hole with 6mm thread
They may not be elegant but they will get you home after a fall.