Here's the story on these -
I bought these lifters from a guy in West Texas a number of years ago, when I was driving through the area on the way from MI to CA. As a teenager, he had worked for the LAW Speed Shop (Jeff Latondress had a post about this place a few months ago) and purchased these using his employee discount when he was working there. He told me LAW repacked GM lifters and sold them as their house brand (you can even see the 5231585 part number on the box), so I am taking his word although if you can discern these by appearance alone, I'd love to know.
These are early 1970s era parts with some very light speckles of corrosion that come out easily with some light oil and a rag. Looking for $350 for the set of 16. Pics below:
