Are these areas in a place where it might make sense to install a gravel guard? If so you might be able to just cover them up with something that would both make it look better as well as protect the area from any further damage.
My 25' Tradewind has the front below the window pitted just like yours. It is from gravel roads etc. I have seen panels for the trailer at Inland RV. I bought a tinted window guard from them for the trailer.