the late Don Zutz was a very knowledgable writer of things shotgun related. His articles appeared in several prominent publications, as Handloader, American Rifleman etc. I could be wrong here, but seem to recall him as being more free-lance & not on the permanent staff of these mags.
I also recall back in the 60's Francis Sell was using perforated or cupped filler wads over a thick card with one of the then new Alcan PGS plastic wads turned upside down as a short shot cup & reporting very tight patterns. For loads which left enough space he used the full perforated filler sandwiched between two .200" thick cards as I recall & then the PGS atop that. If not enough space for the extra card he only cupped the filler to about half it's depth. For 12ga I believe he used a .410 wad cutter & about a 3/8" punch in 20ga (His Favorite in 3" length).
