I have seen this issue multiple times on the forums.
I have a PRD and from what I understand it is the same starter as the Leopard. I had starting issues that was on going. I took the starter apart to replace the brushes. Instead I soldered and RTV’d the brush assembly. That was over a year ago. Vroom Vroom!!! Starts every time. Maybe I was lucky, but it worked and I didnt have to spend the money on a external or a new starter.