Hello all,
I did a very brief Google search and found this image of a campy equipped BMX bike:
http://www.campyonly.com/
It shows the single chainring on the inside, and a remaining, and unused, shoulder on the outside. The timeline there indicates the BMX equipment begain in 1980. Given that the cranks I have are marked with a one in a circle (presumably 1981 then), I'd tend to think these are not an aftermarket anodizing of a refurbished crankset.
Here is the link to the timeline:
http://www.campyonly.com/
Chuck's website lists the BMX cranks as appearing in the 1982 catalog.
rob hawks
richmond, ca