How far back, though, would research have to take any prospective author?  How major a part would 'Ivy League' play?  Would it be necessary to go all the way back to the first appearance of the sack, to repeat the oft-told story about the button-down, the also well-known story about the penny loafer?  Or would it be better to begin in, say, Soho just after the war and feed into it from there?  I don't know.

Thanks, Alvey, much appreciated.  Only J.P.Gaul could probably tackle this with any kind of credibility.  Love the additions.  How could I have missed out Georgie and Ronnie Scott?  So glad my Dad made it to the original club, if only the once.  I have a great black and white of Lambert, Hendricks and Ross hanging up on the stairs.  One of these days you must come and visit.

Everything Alvey says has absolute validity.

The Jewish/American/Italian/Soho/gay influences must always be emphasized - but this could lead to an interesting debate in itself. 
Vestiges of Modernism can certainly be picked up on the current Chiltern Street website, albeit in a slightly contrived manner. 
If, however, I wear a soft-shouldered corduroy jacket with imported Levis and white sneakers it's a direct reference/homage back to a certain time and place: NYC, circa 1959-60.  But it's only a self-conscious attempt to recreate a mood - which of course exists only inside my own head. 
So be it. 
John Simons was (still is) a visionary.  I would take an educated guess that a lot of dissatisfied/disillusioned Mods sooner or later found their way to one of his shops - and thus returned to sanity, creativity, aspiration, good manners, curiosity about food, drink, design, art, architecture, music, the wider world around them. 
But it takes some thinking about.  And that rules out the majority.

^ Right.  I began to get interested in ergonomics and develop a critical eye for design.  I began to take a stronger interest in writers like Ian Nairn, Geoffrey Fletcher and Richard Cobb.  I also began to pay more attention to 1930s Hollywood: look at the sets, the ambience of movies like 'Dames' or 'A Day At The Races'.  I'd already studied writers like William Carlos Williams and Wallace Stevens but was able to move onto Cummings.  Then - art.  Ellsworth Kelly became important.  Hockney - who I'd always admired - possibly more so.  Not much of this would have happened had I not begun to know more about fabric and texture.  The little things I guess I'd already begun to notice by reading Blake.  Also W.H.Davies.  Everything feeds into everything else.  I began to read people like Nader and Packard.  I set aside bits of my formal education and began to think.