The challenge is simple: a present day United Kingdom with gun control laws no more restrictive than the most stringent United States. Having visited the U.K. and being acquainted with several English people, my opinion is that the “right to bear arms” does not exist in a meaningful way for most citizens.
As a resident of Massachusetts, I have the right to own semi-automatic pistols and rifles after completing a firearms safety class, and can carry a concealed weapon after completing additional safety classes and receiving the permission of my town’s chief of police. As Massachusetts is one of the most liberal states in the nation, I would consider this to be a good benchmark.
Considering that the “Right to Bear Arms” was enshrined in the 1689 Bill of Rights (for Protestants, at least) I don’t think this is impossible. Bonus if knives are also legal to carry without the risk of being imprisoned. No PODs before 1920 are necessary, as the before that time the ability to bear arms in Great Britain was a “right,” whereas afterwards it became an increasingly narrow privilege.