Apex Gun Parts (https://www.apexgunparts.com/) has been a vendor of Colt AR-15 parts for quite some time. On 5 August 2021, Apex sent out a sales solicitation email that advertised some Colt ‘M4 Carbine Upper Receiver Blemished’ for sale.
I was really tempted to buy one of these but the sales listing had a disclaimer that stated you could receive a cleaned or uncleaned part. This meant that the upper receiver that you get could be clean and look like new or you would get an upper receiver as it appeared at the end of testing.
The image below shows how each upper receiver was packaged. I would have definitely purchased one if I knew they came packaged like this.
The photos below show some of the upper receivers received by customers.