i got mine from dubmeister at Inters...and i got pulled on Monday night on the way to Leeds and got a fine, i pleaded ignorance but never mind. The coppers were very nice chaps so i wasnt really that bothered. I am still going go keep them on, not been stopped in Preston yet so will wait till i am.
So as gibby says, be careful
I was also told that even if you get pressed plates with UK font they are still illegal due to the reflectivity and other reasons which i forgot!