Now I've always thought that a Delmonico was a bone-in NY strip. Just checked the websites of 2 Seattle area steakhouses (Daniel's Broiler & Metro Grill) and confirmed.
Although I see from the original Delmonico's website:
“The Classic” Delmonico Steak
Twenty Ounce Wet Aged Prime Boneless Ribeye
Wonder how that changed from the east coast to the west?