I mean, what's the point of having a registration code on the patch at all? If you're worried about legal/moral issues relating to the fact that you're distributing these games for free, creating your own registration is one step more illegal than simply handing the game out. A DRM checking if you owned the game might help, but considering it's a game from the mid-90's, that technology obviously wasn't prominent then, and creating a manual trust-based Rights Management isn't really going to help. That is, if Ubisoft gave a damn about it anyway, which is why I find this DRM not only legally inadvisable, but utterly pointless. You aren't protecting any sales; it's not like Ubisoft themselves are still selling these games.
And no, I didn't change my signature.