Recently purchased a Sekai 2700 off CL for $100. The CL ad just said "Sekai Road Bike" with a blury pic and not much more really. I replied and followed through with a tire kicking session and was pleasantly surprised with components and condition of this bike. The original owner said he paid $500 for it new in 1980. Frame is Tange Champion tubing with Suntour GT Derailluers and downtube shifters. I have replaced the tires, tubes and seat at this point. I like steel frames and I feel like I got a bargain here. How does Tange Champion measure up with Reynolds 531, Columbus, etc.?