Ford can get these through official channels.
Just like, how they can supply a brand new chassis and bodywork.. dont know why anybody would want 1 lol, but it can be purchased... and when they supply it, they supply it with the same chassis numbers as the chassis being replaced... because you cant even order 1 without providing ford with the chassis number and build data..Apparently dealers also have to order it through a certain department in ford.. they cant order it directly.
I imagine a similar method would be required just for the Chassis number plate in the windscreen, they would probably require proof of ownership in the form of registration documents, and it would be a dealer only fitment for obvious reasons.. so you cant order 1 and fit it to another car.
What beats me though is how they changed it in the first place.. theres only 1 ways of removing it and rivetting another 1 in place,
removal of the windscreen, or removal of the dash.