I dare say that the term "spanner" would never have entered our vernacular over here were it not for our good friends from across the pond. Who knows how/when/where that change in terms came to be, but suffice it to say it happened well before my days on this earth!
One question: When it comes to the left-handed, metric, adjustable "wrench", would you guys still call that a spanner?!? :-)
For that matter, I have always thought the term "spanner" was best suited to the "adjustable wrench" as it could "span" across several bolt head and nut sizes...
Massey Exposition of North American at Paisley, Ontario, Canada is coming right up!