There are both 2 and 4 coil 6V examples on Ebay. The higher torque starters have the 4-coil setup. For the price, it wouldn't be a bad idea to install a 4-coil assembly. Rust on the pole shoes isn't a problem- - - -loose end bushings that allow the armature to drag on the pole shoes is.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!