I have a Zebrakenko that I purchased in 1977. The lugwork is sloppy compared to other bikes, and has other imperfections. However it rides nicely and the frame is straight, and over the years has stood up to all sorts of riding, including loaded touring. It is possible that the imperfections on the OP's bike are cosmetic. The bulge under the seat cluster may have been caused by overheating, but shouldn't affect the strength of the frame.


Can you ride it no handed? If not the frame might be damaged, if you can, it might be okay.