Remember, sealed beam headlights did not become universal until 1940. I am not certain but I think from your picture your headlight has been converted to a sealed beam. My '37 had a separate low wattage bulb inside the lens. The reflector had two bulb sockets; one in the middle for the dual filament headlight and one near the top for the parking light. Perhaps the '39 had this same arrangment.
Kent
