Thanks for all of the information. I have some long-reach Tektro R556 calipers and they grab the a 26" rim at their furthest reaches, so that'll take care of the braking concerns. What this thread has helped me decide is it'll probably be easier for me to just get a cheap set of used 26" wheels if I can find them. The wheels (solid axle) are from the early 80's, so I think it'll be best if I don't do any overhauling. I'll leave them be and look for a cheap, less headache-y solution. I really appreciate all of the advice.