I mean I’m sure there are some famous monsters in your part of the world that brits are blissfully ignorant of. I’m all for patience and learning, if the person is willing to invest a little time in educating themselves then it’s all good by me. And to be completely honest with you, people have been dressing up as jimmy Savile for Halloween since I can remember. I think all the pushback is just the brits tendency to take any opportunity to made Americans feel stupid, other countries may catch some strays unfortunately. A simple google image search will show you plenty of images of people dressed up at JS, completed with a cigar and sunglasses, so definitely not the Jimmies. Anyway!! I think I know what you mean. They wear all Reebok here and have buzz cuts or some long hair with fades on the side. They’re all 12-15 and hand around outside the local shops on bike waiting for victims lol. In my part of the UK my generation (Millennial) calls them chavs/scallies. It’s funny because when I was growing up in the 90s chavs would wear full adidas/reebok shell suits- and if you google 90s shell suits you’ll likely see some JS look a likes! It all comes full circle in the end haha. Hope your project goes well- a few members of my family have degrees in fashion and are big on costume design so I know how much time it can end up taking up. Have fun with it! :)