The part from appliance parts pros arrived in great condition and fit perfectly. I removed the metal shelf hangers from the broken rail of the old shelf and attached them to the new one. Then I installed the old wheels from the old shelf, front end, to the new shelf in the pre-drilled holes. Note that - as someone else mentioned in the reviews - the wheel holes on the rail support don't really have threads for the wheel screw, so you have to be careful while installing them.
The biggest challenge for me, that made the process take longer than it should have, was finding the right tool to turn the screws on the wheels to mount them flush to the shelf. Using force to insert them seemed to stress the plastic panel on which they're mounted, and I felt that might break the new shelf, too.