This one prompts you to type a literal key sequence (exactly like with `describe-key', C-h k) and inserts it at the point in a representation that the *-set-key functions can use. As written it's bound to to C-c k, and only in the scope of elisp buffers.

    (defun insert-key-sequence (key-repr)
      "Reads a literal key sequence from the user
    and inserts a representation of it at point,
    suitable for `global-set-key' or `local-set-key'."
      (interactive "KKey sequence? ")
      (prin1 key-repr (current-buffer))
      (insert " "))
    
    (add-hook 'emacs-lisp-mode-hook 
              #'(lambda () 
                  (local-set-key "\C-ck" #'insert-key-sequence)))
    
    (run-hooks 'emacs-lisp-mode-hook)

Unfortunately it doesn't seem to work for mouse chords.