Got a couple of bicycle brake levers from a scrap farm bike.
Bit of a mod to were it fitted to the handle bar and connected it up. After drilling a hole through a 6mm set screw to thread the bicycle cable through.
Hit a snag here. The lever not being straight fouled the handle when pulled right back. So I shortened the lever.
Finally I did away with the R clip that held the chain to the location pin. Threaded the hole 6mm and secured the chain.
Might throw some paint at it sometime. Also see if I can find a straight steel lever to fit.
Maybe not pretty but it works and it cost me nowt.