Thanks for posting this, I intend to read it fully when I have time but this bit is interesting for me as I've often felt that 7.5's seem to ride the wind better:
We had ascertained that a light load of skeet 9's would break targets out at forty yards, but Cordaro had made the qualification of not using them in a strong wind. Experiments had shown that strong winds could affect the smaller pellets, in their denser shot column, to point where virtually the whole pattern could be so blown; hardly a pellet would be found on the pattern sheet at forty yards. He had found that the same applied to even to 8's in similar conditions while 7 1/2's would still produce good patterns.