Bring the papers to a LW meetup, and ask people to spend 30 minutes proofreading some chapter. Assuming many of them haven't read the whole Sequences, they can just pick a chapter they haven't read yet, and just read it, while marking the found errors on the paper. Put a signature at the end of the chapter, so it is known how many people have seen it.

Thanks for the suggestion. I'll plan some meetups around this. Not the whole thing, mind you. I'll just get anyone willing at the weekly Vancouver meetup to do exactly that: take a mild amount of time reviewing a chapter/post, and providing feedback on it or whatever.