Did you try looking at the local NAPA or O'Relly's store. The US sealed beam headlights for our cars are really nothing special. These lights were mandated by the US regulations, and are generic pretty much across all range of cars (domestic, etc.).
I did a quick search at K&K, Buds and Millers, and they had no listing for a US sealed beam. Autohauz Az did have some Sylvannia bulbs listed.
I would recommend you take a look at the generic auto parts places. A common upgrade, with very little degradation in looks or need for upgrades is a halogen type bulb.
I believe there were a couple of strings about this posted,try the search function to see. (use the term "headlight" in the search field and limit the search to topic line only, I got three pages of hits. There were a couple of comments about the Sylvania bulbs, and about some conversions that would not require modifications)
Good luck