Owls in the Marsh 1959

Oslo family the Monsens recieve uncle Pavel's house on the south coast of Norway after his passing. Mr. Monsen is also under the assumption that he has won 5000NOK in the lottery, though things are not as they seem. On an old record, the little girls hear uncle Pavel tell the story of a lost treasure buried somewhere in the house, but to find its location, one must solve 4 riddles.