I hate to be the one to write this but it may help you get a better model. You might want to ask the painter to take a fresh look at the bunker numbers.
On the left hand side the last number 4 appears to be higher and tighter to the 7 than perhaps it should be.
On the right hand side the gap between the first 4 and the 7 is wider than the gaps between the 2 4 and 7 4.
Of course this may be entirely prototypical as I've seen this level of variation in photographs, not specifically relating to the E4 class but on steam locomotives in general.