Actually I'm not sure you know.. I don't think the font on the P22 site i.e Underground and the London Tube fonts are correct...
I think the plate supplier is more accurate in the representation as far as I can tell in your images..
Compared...
Look at the R and P's the top portions are elongated, they are not in either of those two fonts. The bottom of the U is also elongated and not in those fonts.
Although I would say the G is probably more accurate in the font sets.