plastic drive wheels?

Very late Ives... I'm guessing a No. 17 / 176, circa 1930.  I hope someone more well versed in Ives can confirm that.  I've seen a lot of different homebrew replacement wheels, but the plastic (Teflon or Nylon, perhaps?) is new to me.  I even had one with old metal bottle caps for wheels!  That must have torn up the hardwood floors...

I think you are correct about it being a #176 from 1930. Everything seems to match up except the nylon wheels. Someone must have manufactured them for this purpose as the rear drive wheels have brass bushings and the drive rods are mounted to a raised nylon ferrule. The pin on the drive rod does not go all the way through the wheel.

The chassis also has the third rail slider as you can see in the one picture.

I have an Ives with that same basic late motor, but with stamped wheels instead of the die-cast.  The body appears to be a 5th series No. 1, but has that very late motor in it.  Interesting to say the least.  It appears to me that this motor has both Ives and AF characteristics at this point.

It never ceases to amaze and confuse me why companies like Ives and AF had such a plethora of body styles with minute differences in their cast iron locomotives.  I would think that they would have made a couple of models, say a small locomotive and a larger locomotive, and stuck with those over the years.  Perhaps a smaller version with a cheaper motor as a 3rd option for a loss-leader.  Could it be that the wooden pattern got damaged or so worn out, that they just churned out a new one, and the differences can be chalked up to the style, taste and artistic interpretation of the current pattern maker?  Or were the little details changed on purpose by the manufacturer for a reason?  We may never know... but regardless, it sure does give us a lot of neat locomotives to collect!