Kids book from 1970s/1980s. Kids solve a mystery based on hidden clues they find – at their grandparents house maybe? I forget where the first clue was or how it started. The second clue (maybe?) is found in a loose stone of a stone fence. Then there’s something about kids being chased by geese trying to get gooseberries. The last clue is found tucked in an Indian Headdress socket where feather would fit in. Thank you! Been searching for years.