I believe you are correct that these are not on all jump strips. This error is like many Canadian coils from this time period that have damage or some other type of variety on the right side of a jump pair. See my FlySpecker article on the last George VI coils for more information:
http://flyspecker.com/285-Coils.htmlI believe the Wilding coils with the broken E also show the same inconsistent appearance. I have been looking for some examples for my site for quite some time now. Below are two links to images I have found online. They seem correct to me. Notice that the variety is much more pronounced on one image than the other.
http://www.mjrpostcardsandcovers.ca...evariety.jpghttp://www.armstrongsstamps.ca/imag...tripevar.jpgIf you have a copy of this variety, please share it.