I recently bought a made-in-China knockoff of the Kurt D-40 4" mill vice, this being a nice size for my Millrite vertical mill. What I got is an Enco SR425-7241, which was on sale plus free shipping.
Price comparison: The same Enco catalog quotes $575.00 for the plain-base D-40 and $86.95 for the corresponding import, so the price ratio is 6.6 to 1.
I had been looking for a used D-40, but they are far from common, so gave up and I got the import.
The import vice seemed to work just fine ex box, although the finish isn't quite polished.
I took the vice apart, and all the expected parts are there, but some are crudely made, and there was some gritty swarf in the cavities.
The half-sphere that goes between the angled driver and the back of the moving jaw block was very crudely made, with a big machining center pip that dug into the face of the angled driver. Cleaned up with a file and some sandpaper.
The angle was left as cast, so I flattened it with a file, so the flat side of the hemisphere can slide around freely. The spherical socket in the moving jaw body was also as cast, not machined. Mated the socket with the hemisphere using some Clover grit-in-grease and much elbow grease.
The 8mm square key that fixes the stationary jaw to the vice body was too big for the slots, and had been forced into the slots. Carefully filed the square key down a bit, so it's still a push fit, but not a press fit.
Deburred everything, even the hardened jaws. The burrs were not hard, and there was thin decarburized layer, so I was able to ease all edges and corners.
All this took two or three hours. The vice has a very firm grip on flat stock, and the jaws do remain parallel, but I don't think that the movable jaw will tilt from side to side much. I don't know how much side-to-side motion the Kurt vices can manage, but this is a claimed advantage with stock that is tapered.
Now, the long awaited perfect used D-40 with swivel base will turn up.