I have the hardwood floors from the 1920s as well. No scratches, except the ones I've made by accident.
Thor also does the "yabba dabba do" on them, AND when he chases things down the hallway, he skids several feet before he comes to a halt. I can hear those little nails screeching, but I don't see any damage. He really has it down to a science.
I say, get really good, protected hardwood floors, and enjoy all the extra cuteness.