If you head to a wrecker you can get Halogen ones that fit and look very similar from an MX5 or Honda City or the like. Otherwise try SuperCheap, I am sure they did stock the Sealed beam ones, but to be honest if you are going to drive the car in the dark the Halogen are well worth it.
I may have one here I have replaced if you find them hard to find and authentic is important to you.