the font in the word Everest...and as you point out, the position. The font on yours is the same font as used in the word Rolex...and it sits farther down from the Oyster Perpetual than Oyster Perpetual sits from Rolex.
The font for Everest on my 5505 matches the font for Super Precision (look at the Es and Rs) and sits almost the exact same distance below OP that OP sits below Rolex. Since I don't have pics of my previous 5505 I can't compare...though I vaguely remember that when I looked at my first 5505 I felt the lettering was struggling with the surface irregularities of the honeycomb dial.
Since this was a limited model for the Canadian market, I wonder if Rolex also experimented with fonts or if they had more than one dial provider or set of specs, depending on the size of the honeycomb.
I assume your 5504 is with the 36mm case and 20mm lugs, as are the 5505s.