Another issue here, which I forgot when I wrote my original post on the subject, is that stock racing frames from the early part of the century tended to come in few sizes. Small, Medium, and Large were about it I suspect, and people who were in between sizes probably chose the bigger frame, because, all things being equal, it would have been more comfortable if set up properly.
And, there may have been a fashion-statement in these choices too, as Sheldon points out.
Charles Andrews
Los Angeles