Major Boothroyd was a real person. He wrote a letter to Ian Fleming telling him how much he enjoyed James Bond but telling him that a real agent would not use a .25.
He and Fleming became friends and when asked what type of gun a real secret agent might carry, he told him a Walther PPK in 7.65 knowing it was not really powerful but in fact was a common choice.
Major Boothroyd was embarrassed when Fleming described the .32 as hitting like a brick through a plate glass window.
In Dr. No, Fleming used his real name and that character later was stretched to be “Q”.
Looking at his wiki page seems he designed the fitz special or copied it. Got to go do the math and see who was first Fitz or Boothroyd..... Interesting folks