Joe, that's pretty cool, although you reproduced a worn-out part with another "worn out" part (same contours of the broken, worn out one). With a little tinkering with that 3D printer you could adjust your pattern to get closer to the contours of an original non-worn part. The groove in it should be just a bit larger than the rod.
I didn't know there was a 3-D app for the iPhone. I may have to mess with that.
[on edit] With your permission, I'll change your PDF attachments to photos, which appear better on the site.
It may be better discussed here in the Tool Chest forum. I'm sure that there are guys who would be interested in more detail.
