You could probably get all the illumination you need by adding a reflective strip behind the bulb to reflect light. Some original installations did just that using reflective cardboard.
Most hobby stores carry large 3 foot chrome self adhesive vinyl sheets for R/C plane graphics, you could also try the self adhesive foil tape for furnace ducts, some brands are very shiny.
Put that stuff on some sturdy matt board, mount it behind the bulb with a couple of lengthwise folds to direct the light and I bet the results would be great.