AFAIK there is no such adapter, you just plug the FliFi partt of the PIV into the A2k video slot and connect it via ribbon cables. So no extra adapter needed.
@Vlabguy1: which socket does the adapter fit in your Amiga?
The adapter exists (have a few unpopulated PCBs purchased some years ago from the Masta himself). I believe it was for using the PIV flickerfixer with the video slot already occupied.
A few
gallery shots from user trilobyte.