Hi Korey,
The only nylon part inside is the arm that pushes the axle. Reduction gears are iron.
The brushes kit I ordered is this one : http://www.condensateur-web.fr/couro...A2452-298.html
It needed a few adaptation : drill 2 new holes in the starter rear cover and cut 1 little centering finger on the brusking frame
Then I ordered a HK2216 bearing from SKF brand.