Reply to "Engines Requiring Large Radius Curves--why?"

A friend that's into "O" scale fell in the same dilemma when he built his layout in the 90s. Short of restarting, when he wanted bigger engines, he started looking into many of the scale K Line engines which would negotiate the curves. Many of K Line engines equal some of the newly highly detailed engines and can still be found at reasonable prices. I believe his biggest radius is 048, but he has K Line scale  Hudsons and Berkshires running.