Hello, and welcome to the Forum. I was lucky enough to get a large mailbag of these type of Newfoundland stamps, and found many different oddities. However, I feel your pain for this issue.
One thing to consider is that the 2c King George VI was issued as the Royal Family Issue in 1938, and again by Waterlow in 1941 to 1944. The perforations are slightly different, but the easiest way to see if you have Unitrade 245 or Unitrade 254 is by the curvature of the bottom of the L in Newfoundland. See these side-by-side scans, which has 245 on the left, and 254 on the right. These could help you differentiate your stamps.