I don't have those but I do have black Astrolorps...all black. When they're scattering in panic I can't pick one out of the flock but when they're just being their normal selves, I sort of can.
By behavior. And who they pal around with.
But I know they sell leg bands for birds. And I read on here someone painted their birds toenails.
I don't see why you couldn't notch a wing feather or two as well: Debbie has one wingtip notch, Sassy has two, etc. In certain countries they notch cow ears (owww!) so clipping the very end of a wing feather for id purposes wouldn't be painful like that.
Your saying that the only way to tell the difference is to know how they were bred?Do the gold comets?production reds,red star,isa browns all have the same laying qualities?thanks,,
Gold comets, isa browns, red sex-links, etc. are all basically the same thing. These breeds will be a light red color and will have some white in their tail, neck, and maybe some other parts.
The Production Reds will have black where the Red Sex-links have white.