I promised details about the current project, and even though it's still not done I'll share. Ages ago we pulled up a bunch of the original pine plank subfloor from the first floor. It's been so long I can't even remember why we ripped it out, but we saved it knowing we'd reuse it in the attic. Hauling the wood takes a long time, in part because the contractors decided that our relatively neat stack of flooring downstairs was the perfect place to throw dimensional lumber, unrolled batts of insulation, old shelving, and other miscellany that still had 3" nails hanging out of it. My neat stack turned into a jumbled tangled mess with no organization - they didn't even bother laying it all in the same direction. On the plus side, that big mess is slowly disappearing as I install the floors.
I'm only about a third of the way done, but I'm loving them so far! They'll never have that perfect glassy gym-floor shine, but I'd take these nail-pocked 100-year-old floors over that any day!
I have been using my 16-gauge finish nailer to nail them down, which means I have to follow up with a hammer and nailset to make sure the nails are countersunk. Yes, a flooring nailer would be faster, but I don't want to buy yet another expensive nailer. I'm keeping an eye out for one on Craigslist (since I don't think I'll want to install the floors downstairs this way). Renting such a small piece of equipment for a few days costs about the same as buying the darn thing to begin with. Finishing the floor installation is A-#1 priority for the week's to-do list.