I just bought some of these, and after comparing them to real and fake pictures,and getting background information on the seller, I am very certain that they are genuine.
They are an auto parts wholesaler without a single bad review, and after messaging them, they told me that they bought them in a huge Denso auction, and nothing about them screams "fake".
I also personally took one of mine apart and yes, it's definitely high quality, matches OE pictures exactly, and I took out the pump itself to match against "real" and "fake" pictures, and yeah they're pretty much real.
They come with the factory manual and harness as well.
This is a once every few years kind of a deal!https://www.ebay.com/itm/Denso-Fuel-Pum ... Sweqpel2kl