Bert, your comments are valid 
This is a dell reinstall disk, not a full XP disk. 
While they could have copied and screensilked the disk, I suspect these are genuine, as these folks seem to be legit. Because of the limited market on reinstall disks, I suspect it would not be worth it for a legitimate company to incur the wrath of Microsoft/Dell/etc. 
I have dealt with them before. Actually, never bought the disk because I didn't have a need for it. So, caveat emptor.