As far as I have been able to find out,despite what the rules state and makers seem to think."or interpret",it is not illegal to make a plate that conforms in type,style and size with the year of the car it is going on!!
Apparently there are sufficient loopholes!
They also say the maker has to put his details on the plate,but if no details are put on it then theres no proof who made it!
It all came about with scum who ring stolen cars,but that wont stop them,they can easily make their own plates!!
Most of the dealers cannot be bothered with the hassle of getting the correct materials in to make them,as the market is somewhat limited!!
There is a plate maker who attends classic shows in his trailer,who makes pressed and plastic plates on the spot and will take orders for more the complicated "older" style plates.
But I dont have his details to hand!!