Doug,
the pic of the Parker shows the lines of color on the frame and forend iron. The belly of the Fox shows spotting almost like water splashes to me. No lines of color like the Parker. But I do agree that both are cyanide casehardened, just done by a different process. My understanding is that there is a stepped immersion to get that striping look. I beleive the Fox is immersed in the molten cyanide salt bath all at once.


Here's a pic of a Trojan, stated by the owner as a Del Grego restoration. The tiger striping is clear.