Mine was missing them when I bought it. The parts are expensive because they're relatively rare, the only reproduction housings are fiberglass, and they're used for rat rods and hot rods as well.
I have seen the replicas available,if I am not mistaken one company lists them as steel.
What blows my mind is the price of the chrome trim rings,$72 per when my 56 MG has the same thing and size at $17 per new.
By the time you get the housings and gaskets and glass lenses and outer trim ring it comes to $100 or so per light.
But it seems like everybody is missing their headlights because when they come up complete they sell around $200 to $300 for a really nice complete set every time.
Last Christmas there was a really nice set with no dents and nice chrome that sold for $135,I never bid on it because I thought it was going to bring all the money.