My assumption would be that they’re not made in house. I don’t know for fact, but I believe that stern would outsource as much as it can to save money, as long as they are able to keep their “made in America” sticker on the glass. I dont know for fact, but again, I’m assuming that their toys, mechs, plastics....whatever part you can think of is probably made in China and shipped to the USA and then assembled in Chicago.
My GoT topper’s install documentation doesn’t mention anything about made in America in it. And without taking off my game I didn’t see a made in America sticker on the back or top. I’d think if it was made in the USA then stern would advertise it.