Ludvig k Mathisen 1856-1917 Tonsberg Norway.

Im trying to find living family members of the descendants of Ludvig Mathisen Notteroy near Tonsberg Norway. He had five children Rolf, Sverre, Athur, Magdelene and Anna. My grandfather Sverre born 1890 went to Australia and Rolf went to Texas usa. Anna was the youngest born 1899. Artur or arthur had a resturant Valkyrjen in Oslo he married Annie Henrikke johnsen born 1887.I come from newcastle nsw Australia and although i have found a lot about my ancestry i'm lost to finding living family members. could you help me as we are coming over to have a look around Tonsberg in August. Paul O'Neill