Just do it! There was a image posted on this forum some number of years ago of a KF flying without rib stitching. Most of the fabric on the top of the wings had ballooned since the image was taken from a chase plane. We took the class at Oshkosh, but the DVD video is better. After the 1st rib, stitching become very routine. Just be sure to have plenty of band aids for your fingers (you'll understand when you pull the twine tight). My wife did >1/2 of the stitches on both wings. Nothing to be afraid of, but buy the video.

BobRS
KF SS7, Rotax 914 and Flying
Albuquerque, NM