monster s4 starter problem

Been having major problems with starting my s4. After reading all the posts about starter problems i eventually narrowed it down to a faulty starter. To make sure, i removed the RH cover and found that the rotor (where the brushes contact) is breaking down and some parts have even melted!!!

I know that i need to get a new starter, therefore i have to take the LH engine cover off, but i was just wondering if the problem could have been caused by a faulty free wheel unit (Sprag clutch) or is this wear and tear on the starter.

Anyway if anyone has a starter or any advice on how far i could go with reconditioning, i would very much appreciate hearing from you.

cheers

Jim