I emailed back and forth with Nestle England years ago and felt confident in giving them to my son's at the time. If I remember correctly they labeled for shared lines as a contain. But no, it's not as clear on the label in regards to say Hershey's on what it contains at the end, kwim?
Our Publix carries a variety of the Aero bars and a few others but I often get frustrated because I have to peel back the "USA" label to find the ingredients. I wish they would carry more
I do shop at our British specialty shop for the Smarties and I think Kit Kats (was really peeved at Whole Foods when they stopped carrying them).