Originally Posted by
Velometry
there is a guy in Poland that makes an adapter that fits in the large pedal hole and converts it to a size that fits modern pedals.
Yes,
"Racevelo," who also makes reproduction vintage brake lever hoods, a tool for pre-1982 Stronglight cranks, and other stuff.
Shimano made their own adapter piece, so AX cranks could use standard pedals, but it's hard to find these days.