I think the Walthers Brach's Candy hopper
I built recently was also stamped from Denmark.
I bet most items that we see that are stamped from Denmark are Heljan
produced, but I've not seen any firm evidence regarding US prototype models. A fair amount of ConCor product was Heljan produced, but I don't recall if that extended to rolling stock or if it was just structures.
I think Heljan moved production to China, but I'm not sure when or how much.
My family is half of Danish heritage, so I'm always interested in anything Dansk.