making new frame display the same font??

[Fortepianissimo]

Please forgive me if I sound totally ignorant - I'm using Emacs 21 on
Mac OS X. I've set my default face in my .emacs as follows:

(custom-set-faces
  ;; custom-set-faces was added by Custom.
  ;; If you edit it by hand, you could mess it up, so be careful.
  ;; Your init file should contain only one such instance.
  ;; If there is more than one, they won't work right.
 '(default ((t (:stipple nil :background "grey95" :foreground "black"
:inverse-video nil :box nil :strike-through nil :overline nil
:underline nil :slant normal :weight normal :height 104 :width normal
:family "apple-monaco")))))

But the problem is whenever I hit c-x 5 2 for a new frame, the font
used in that frame reverts back to the default (larger) one.

I've been trying to find myself some tips over newsgroups and heard
something about initial-frame-alist and default-frame-alist. My
initial-frame-alist is nil and here is my default-frame-alist value:

((tool-bar-lines . 0)
 (foreground-color . "black")
 (background-color . "grey95")
 (menu-bar-lines . 1))

But I have NO idea how to achieve what I want (which is a darn simple
thing I would say). Could anyone give a hint or two as to what I
should do next?

THANKS a bunch!