Not sunrays, it�s definitely a wheel as stated. I would guess a racing event of some type. Racing cars of that era had spoke rims. 1938 race car Grand Prix, Motorcycle Grand Prix or hill climbs maybe. Quick guess on the flags? Belgium, Denmark, Germany, UK, France, Italy, Yugoslavia and Switzerland. Country's that participated in the event or where the events took place. My best guess anyway and hope this helps a little.