Hi Jimmy!! That is certainly an excellent question and one that many of us collectors have had to tackle. Typically, there are a couple of key signs/points to look for:
Please notice where the "V" in George VI sits above the "W" in Crew. The point of the "V" should sit directly above the first line or left portion of the "W". If the point of the "V" sits directly in the middle of the "W", it is a copy.
The other easier sign I personally look for is the "E". The three horizontal parts of "E" are same length on copy. On the original the central horizontal is shorter.