If I'm reading the above correctly - The Reproductions and the originals were case colored in the same fashion. The only difference being the lack of "coating" on the Reproductions.OR the originals might have been Bone Charcoal case colored,
Glad that was cleared up.

Does anyone actually have a definitive source for either position?

I've seen plenty of "old" Parkers with essentially no case coloring left on the exterior. Does that indicate that the cyanide or just usage?