I came upon one of these locally, at a low price, so I bought it.
Thanks to it's relatively simple construction, I was able to re-lube the the focusing helicoid myself.
It's difficult to precisely focus at f/4(using a stock D800), but I've recently been amazed at the detail it produced in this shot at f/11; focal length uncertain, 40mm or maybe 35mm(I tend to stick to the marked FLs until I learn a new lens.)