I don’t know what has previously been said, as I haven't yet had time to read through all the posts. However, I was appalled at how the series appeared to glamorise a bunch of thugs. As far as I could ascertain, only the beginning of the first series had anything to do with historical reality - apart from the bit where ‘thingy’ rides in on a white horse - which was almost an exact rip-off from an American film (sorry, I forget the name of the film).
I notice that Professor Carl Chin wonders as to the reality of the razor-blades under/within the peak - he opins that ‘safety’ razor blades were a new thing, and relatively expensive, and thus doubts their use. I don’t know about that, but it’s certainly a dangerous practise for the wearer, let some poor victim!
As my old Dad once told me, a more likely method, less dangerous to the wearer, and far more practicable (?) was the stitching of deep, ‘U’ shaped fencing-type staples within the brim. These were attached on a loose, ‘looped’ twine, that could be mostly retracted from view when necessary, but would be released/propelled forward, when the cap was swung in a violent arc. I’ve tried this out for myself (strictly for the purpose of historical accuracy!) with an old cap, destined for the bin. It works, and is not likely to lacerate the fingers of a forgetful wearer! At most, you’d suffer the odd prickle.
PS. I quite understand if the above paragraph is deleted by Postie, for fear of encouraging idiots to emulate, for nefarious purposes!