Reply from Serge Rosmorduc:
"> The hieroglyps look as if done several times over, retouched
> by applying a plaster and thus changed in their reading-meaning.
I agree. It also seems to me that the scale changed : the quail sign is on a much smaller scale than the 't'-bread loaf that covers it.
Have a look at (a sample)
You will see that the small part is simply the titelature of Ramses II: Nbty mk kmt waf xAswt, nsw...
The two mistress "he who protects Egypt and Repells the foreign lands, the king.."
The big signs are also probably a part of titelature : You can see a bow above the 9 ticks, partially melted with the quail and the rest of the arm sign above the "foreign land signs". The sign just before that (to the right!) are part of a word ending with the "armed arm" sign, a determinative of violent actions. Likely an epithet stating that the kings does have power over "the nine bows", a designation of Egypt's neighbours.
I suppose the big signs came second, as they seems to be carved very deeply.
So, nothing very exiting, but an interesting example of a variation of the decoration during the same reign (probably)."