Pvc pipe top cut flat get bike grip cut off widest part of grip closest to center of bike. Put epoxy attach to pipe and you made a nice handle fairly cheap.
Les
You could probably get some 3/4" emt conduit, find someone with a pipe bender to bend 45 degrees on it, and it looks like the 3/4" would fit inside the existing part, which kinda looks like it already has screws to hold on the handle.