Scored a Shimano 600 crankset for 8 bucks at a swap last summer that looked like it got dragged behind a truck. The drive side arm had deep gouges and the rings were toast but the spindle and arms were straight, so I hit the whole thing with a wire wheel, sanded out the worst of the marks, and polished it up. New chainrings for 30 bucks and it looks almost new on my old steel frame. That spider story is great, sounds like the bottom bracket was basically a tiny haunted house before you got to it.

Did your neighbor happen to mention what's actually in that grit? A buddy of mine bought a 1954 place over by Ridgecrest and did the same carpet pull. He figured it was just old dirt until he sent a sample off to a lab, and it came back with a mess of stuff you don't want in your lungs. What got him was the walls, not the floor. Every time he bumped one while hauling carpet out, a puff of fine gray powder came off the sheetrock. He ended up taping plastic over the doorways and running a box fan out a window with a filter strapped to it. The misting trick works, but watch how much water you use on old wood floors or you'll trade a dust problem for a warped board problem.