There's a fortune to be made in an old pair of jeans. The only caveat (and it's a big one) is that the pair has to be really old; over a century is a good starting point. If you do have access to great-great-grandad's wardrobe (and assuming he wore jeans), the old pair could sell for close to $150,000. Lynn Downey, brand historian of Levi's travels the world with just such a pair; quite literally one of the first branded blue jeans ever made.

She ensures the jeans are always part of hand luggage; this is one item of clothing that cannot be trusted with airlines. The other pair she's exhibiting is a 501 from the 1980s. What it lacks in vintage pedigree, this pair from Japan makes up for by sporting the signatures of all the members of The Rolling Stones....

Brand historians or archivists are quite popular among American brands with a long pedigree. They are (or have been) present at Coca-Cola, Disney, Ford, Hallmark and Wells Fargo. And yet, according to Downey, having a brand historian shouldn't just be the preserve of older brands: "The day you start your business is the day you start your archive. I hope Google have an archivist because they are making history."...