In the US most woodturning/woodworking supply stores carry kits. In this case I took the guts from a Harbor Freight screwdriver, turned a new handle out of cherry, filling the cracks with colored epoxy, made a ferrule from a brass plumbing fitting, and put it all together. The handle is finished with Danish oil.
I'm more into metalworking and I'm not that good with wood, but I've made quite a few handles for files and other tools. I've used boiled linseed oil for finishing mostly because that was what I had but the handles get dirty and ugly almost instantly. Is Danish oil better in that regard or would you recommend something else for oily/greasy use? Oh, and your handle looks way better than mine, I need to step up my wood game. 😀