Lower Rack:
The fix was fairly easy, only challenge (minor) was making sure the wheels were put on the lower rack correctly. We did find that the new wheels provided tended to bind in the rear when pushing the tray in, We replaced the new wheel set (rear wheels only) with the wheels from the old set and it works fine now. Hopefully no rust for several years.
Upper Rack:
This required a little more work in that the wheels and the center spray assembly needed to be pulled from the old unit and installed on the old. The wheel set removal required a star type screwdriver.