When Antiques Roadshow needs to know about an old book or manuscript, Ken Gloss is the guy they go to.
He runs the Brattle Book Shop in Boston. It's been open since 1885 and his family has been running it since 1949.
A lot of old books, pamphlets and other documents have personal value - your great-aunt's wedding program, for instance - but figuring out which objects have a more universal value is something Gloss has dedicated his life to.
He comes to Maine a couple times a year and the shop is open Monday - Saturday.