Most pinballs that I played in the wild were between 1970 and 1983. I only remembef 3 NIB unboxed at the arcades. One was a BK at Hurstville where the operator gave me the first 5 games. I think most operators back then gave the machine a good test at their depot and then took them to sites. Most kids back then were on the lookout for new machines as they played so well. Mind you, the operators were much better back then at servicing and keeping the games tuned. A lot of times they gave the kids free games after servicing a machine.
