OK, it looks like in the 2012 version of the SCD, this was changed to Marquard. You can see this on Google Books here:
Link. I would think that with this information, PSA and SGC should change it to Marquard even if it were possible that the artist modified the drawing slightly to resemble Ruth more. (BTW, I am not the consignor for this item, but I was seriously thinking of bidding strongly for it because Ruth items during his Red Sox days are so tough. I will pass on it now.)