I came across that a week or so ago. Bit scary.
I know there are a couple of places that stamp new vin tags for people, but you have to send your original tag for verification. Hopefully this fellow does something similar.
For people that need to repair rust in that area, and who aren't trying to be dodgy by changing any of the original numbers, it would be quite good. I have seen Restore-a-Ford in the UK do up a new strut top panel this way for an RS3100 rust repair where it simply wasn't viable to repair the section.