I restored one some time ago and it ran great. I was pleasantly surprised at the "giddy-up" it had. They guy I rescued it from told me it was "nothing more than a moped". Well, it was much more than a moped, I assure you.
I found a 350 GTR nearby that was for sale and my wife told me I had to part ways with a few bikes before I was allowed to have any more. Unfortunately, the 50 had to go.
The kick start shaft itself is a pretty straight forward swap out, but there is a lot of disassembly required to get to that point.