You can get an aftermarket LED bulb that has the glass flutes which appear much like the stock bulbs. LEDs draw very little current and provide a LOT more light output in lumens.
They are PAR36 12V DC bulbs and they fit the road lamp housing. Bargain price, too.
The application is landscaping hence the 12V DC.
Alternatively, you can purchase the reproduction incandescent bulbs. Dim, use more current, may work better with auxiliary relays installed to provide full 12VDC.