Product review (5 stars): High quality factory replacement
Here's what I can tell you about the part that was 'sold by Amazon', not a third party seller:

1. The motor and fan blade is included. You will need to attach the plastic fan, which had a stop at one end to make sure you don't put it on wrong.
2. The part appears to be a genuine Whirlpool part and of high quality, but not exactly the same as the one I had (see pictures)
3. This fan sounds a little different than the old one ever did. In my opinion it's quieter.

Total job took about an hour, but I took the time to straighten fins and clean the entire freezer compartment. The refrigerator fan/compressor ran for nearly a day afterwards to catch up from being unplugged, but now seems to run a lot less than it used to.

I've attached photos showing the difference between the old part and the new part, as well as the genuine replacement packaging I received.

In summary, I paid a little more for this part than a generic replacement and I'm glad I did.