There were lots of grungy spacecraft in Bruce Stirling's Schismatrix stories, which were published before Mir got off the ground. It's one of those rather obvious details that writers rarely bother to address, or assume will have been taken care of in some manner. For another example, I was just reading a story in an anthology which deals with the aftermath of an alien takeover of Earth; the hostiles take care of humanity simply by removing our ability to read. No jet fighter dogfights or cylinders/tripods needed; over we keel, in short order. I'm thinking your typical aggressive alien species won't want to duke it out with us if at all possible; why not a genetic weapon of that sort, or Heinlein's Rods of God or Disch's 500 foot high weeds?