Yes they did. Can state this as fact as I was in the truck on many visits to the wharves to pick them up. Definitely EMs. Dad used to fly over to the Bally and Gottlieb factories, choose the NIB games and then use second hand games to "fill" the container. Sometimes pinballs and EM games like gun games and novelty stuff like "bulldozer" and "Whirlybird". Then the video games like "sprint", "Le Mans" etc etc. Juke Boxes etc..
Same with the 80's. NIB containers and then fill with second hand games. SYS1 games and Williams SYS4/6 had strange configurations with transformers. I don't know why. It might have been a transition period. I know that domestic EMs simply had 110V transformers and export had 220/230/240 transformers. There was simply a jones plug that you used to set between 110V/240V next to the transformer.