At the time 20mm was the smallest figures you could get. I dont think Peter Laing 15mm when then available.
This did not stop intrepid Wargamers experimenting with smaller scales.
In the magazine was an article on using screws to game with. What is even more surprising is that they were used individually and not even based multiplly on stands.
1/4 screws fot infantry is very close to 6mm.
I wonder if anyone actually tried this at the time.