From a post to Fountain Pen Network by @stoen.

"...a very distinct variation of this model - I find it worth mentioning. I haven’t been aware of that at the time this model was “on schedule”. So, please pardon my late post.
 
I formerly thought it was kind of accidental, “black sheep” variation  unworth mentioning until recently, in private research, as I came across such a series of 101N, substantially and consistently darker than the “regular ones”, with the distinct dense longitudinal celluloid pattern and black ebonite mechanisms. Although they haven’t been catalogued as such, AFAIK, I believe they were more of a regular, legitimate variation, than kind of accidental exception. 
 
Although pretty rare nowadays, in my research such pens have been reported to me by professional pen restorers. They have reportedly been sighted mostly in Central Europe and may have originated from the Vienna and Zagreb factories. Now I have two of them in posession:
 
All other features are quite consistent with this model generation. The only distinction between generations is the Pelikan logo on cap top.So far, there’s no evidence the model has been manudactured past 1940 (injection moulded barrel), although I’ve seen one with the celluloid barrel and black elastomer piston gasket (later repair ?).

A similar variation, although with black ebonite cap top, had been discussed in detail in Pelikan’s Perch."