This was back in the early 1980s when I was running a restaurant in a shopping mall. The delivery guy for the local produce company (his family's business) was a gun guy and had an Auto-Ordnance Thompson semi-automatic carbine to sell. We made a deal on it and he delivered it to me in the parking lot from his delivery truck.
When he originally bought the Thompson it was from a sporting goods store that was downtown in the city...he said when he bought it he simply carried it down the street to his car. Try carrying any gun much less a Thompson down a city street these days!