hi,
why don't you fashion yourself a leather sheath instead of going to the trouble of using bamboo? I'm Madurese and I think most, if not all, Celurits sheaths are made from leather (dunno about the old ones though).
some info about how to make leather sheaths and hotwaxing it (to some extent as strong as wood) could be seen here:
http://outdoors-magazine.com/s_artic...id_article=192
hope it helps