hmmm... I wonder, if they are painted on dry wall - if you could cut out the areas that you love the most - and then re-drywall where you cut them out? I personally don't know how you go about this, but I did live through a remodel once where the walls were all dry walled, and they cut out sections of wall that were damaged, and then fit in new drywall where they cut it out. Once they were done, you couldn't tell which was new and which were existing.