Swan Brewery Letterhead 1871

This is a photo of a Swan Brewery Letterhead dated 1871, indicating brewers and bottlers of Pale Ale, XXX Ale & Porter. For five dozen cases of Porter the cost is $15.00, which works out to who knows what depending upon how many bottles were in a case, doubt they had six packs in those days.......courtesy of the Wells Fargo Museum in Old Town San Diego, which has had this invoice on display for at least ten years. Tried to get this out of them, but no luck......Sorry about the quality of the photo but it is behind glass and covered by plastic, so gentlemen this is as good as it gets.