Picked mine up from the local Moss dealer today. They are different from original, indeed. Green plastic lens is lighter in color. The chrome cap on the lens does not curl over the edge of the lens, as does the orignial. The cut-out arrow on the chrome cap is smaller than original. Made in China. From ten feet, few could pick out the difference, but to those who know, a close look reveals the truth.
The reason you can't buy just a replacement lens, apparently, is that it is not made in the original thread size.
If anyone knows where better reproductions are available, please let us know.