Oh

they can have a different place of birth on each census - that's what makes it more challenging

However, the 1881 one that you posted has Edward b. Chirbury, Shropshire
I've also seen Church Stoke mentioned - which is half way between Norbury and Chirbury . I don't recall seeing many Montgomery place names in the refs.
Thomas, Edward's father, matches on my 1861 and your 1891
gnu
PS - no birth registrations for Edward on the North Wales BMD and Montgomeryshire is complete
