Vintage F Dick 12" Lobster Splitter / Chef de Chef with slightly more recent custom made  ebony handle held fast with four pins and one loveless / birdseye rivet. 

It's hard to put a date on this knife as the markings do not indicate date of manufacture, F Dick made deep stamped carbon steel knives up into the 80s, the original handle would have had lots more clues as to date of manufacture but it is gone. Happily it's replacement is quite nice. 

comes with freshly convex sharpened edge

12" cutting edge, 3/16" thick at spine, 2 3/4" wide 18.25" overall