It is hard to get a feel for the age of this mug only through internet pics. If this was a late to recent souvenir piece, I would expect to find at least a few examples on the web and I have found none. Now if this was an early period piece, I would expect to find almost no examples on the web, and there are none. Now if the potter sold souvenirs, I would expect the output to be limited and most examples discarded/broken/damaged over time. Just my thoughts as I know very, very little about pottery.