The flat vertical mounting pieces for the 26r headlights are available from Kelsport and TTR. As far as the rest of the bucket, curved or square, apparently this must be fabricated.
I have the vertical fiberglass pieces from TTR. Really not much to them. Just cut from a thin sheet of flat fiberglass.
As TTR told me, closing the pod off with bottom and side pieces is according to personal preference. Many 26r cars just leave it open.
Here is a picture of a "real" 26r that shows the area as open:
Here is a picture of Leno's curved version, apparently fabricated. Looks like the headlight holder and curved portion are an integrated unit. Note it was just left as unpainted metal:
And, here is another approach, a fiberglass box, as per member "Mister E". As you can see, at least for a dark color, the squared off version looks pretty good.
Probably, the Leno curved version is the most ?finished? look. I was thinking of trying to use thin aluminum sheet to achieve this curved type.
So, take your pick, but I don?t think there is a ?plug and play? version that you can purchase.