Hello, I am pretty new in the fountain pen collection although I am using fountain pen since I am 15. I recently bought Pelikan Souveran M 600 with a fine nib but as far as I see on the reviews all the series up to M 800 have 14C nibs. And I am pretty suprised when I realized my nib is actually 18C-750. I am not sure if the nibs of M800 or M100 is interchangable with M600. Should I feel lucky on that? Thanks for replies!