Are you taking it to a pinball show, and returning to the states with it?
Is the machine being sold/purchased? Is there a transfer of ownership?
https://www.crossbordershopping.ca/duty-tax-import-guide/duty-tax-tips
the goods are for your personal use; and
they are marked as made in the United States or Canada or not marked or labeled to indicate they were made anywhere other than in the United States or Canada.