Philip Koehring Is Found SlainMAUSTON, Wis., Oct. 31—(UP)—Philip Koehring. 50. road construction equipment manufacturer, was found dead in a field near here today, with a bullet hole behind his right ear and a badly fractured skull. Although they believed Koehring shot himself, police authorities were Investigating possibility of murder.Koehring was president of the National Equipment Corporation, and secretary’-treasurer of the Koehring company, Milwaukee.