To my knowledge, the headlight buckets are not reproduced by anyone.
At a minimum, 1955 and 56 Ford car headlight buckets are the same, maybe some earlier models as well, but not sure.
The need for replacement could be if the part is rusted out at the bottom or damage from a collision.
The bucket itself is a hat-shaped sheetmetal part that screws on to the headlight flange of the front fender. It contains a headlamp mounting bracket made of potmetal that fastens to the inside of the headlight bucket with a spring and two adjusting screws. The headlamp mounts onto the mounting bracket with a stainless steel retaining ring with small machine screws.
I have encountered many headlight buckets that were rusted out at the bottom. If you can find a junkyard that still has some old cars left, you might find some of these buckets that are still intact but the best bet would be to try to get them from the dry southwest, like in Arizona. Maybe Black Canyon or Hidden Valley auto parts. Hidden Valley used to take orders over the phone and ship out to your address.