Members of the public are invited to bring an antique or collectible to the Duluth Depot's Great Hall for a free appraisal. Dan Sershon of Northland Estate Services and Denny Mager of Northern Specialty will offer their opinions on the value of submitted antiques. People may bring up to two items for an informal oral identification and evaluation of each antique. If the piece is too large or fragile to be hand-carried, clear photographs with a description of any marks…