Kenny Priest who used to run The Pinball Warehouse up here in QLD used to use a very similar technique when fixing playfields properly.
He used to print directly on to that clear thin plastic sheeting, then place that clear sheet with the artwork onto the playfield, but it was glued down using a special sauce/glue like u see in that youtube video, and when the job was finished, u couldnt even tell the repair was done or even feel the edge of the overlay cause he would clear that area. It was also extremely durable.

It seems there are a few versions of doing this, and they are all superb for transferring artwork. Thanks for sharing. Great video.