I have just taken the starter apart and noticed that the brushes are almost at the end of their service life, would a kind soul know where to get new brushes from?
Take one of the brushes to your local automotive alternator/starter rebuilder. They will more than likely have some that will work. Nothing magic in those.
Panama Marine, Panama City Fl, 850 785 4661, has ad all the parts I've needed for my 70 Hp Johnson, and they will drop it in the mail for you.
Good luck.