I think your best bet will be doing what I did originally.
Contact one of the many sellers on Ebay of "Show Plates" and explaining what you want with the Tickford logo middle bottom.
I just had a quick look and there are loads doing them for around £20 a pair.
Send them a picture of my K9 plate
So they can see the size of the logo in relation to the plate.
See what they say.....