I'll throw my own two centavos in here. I completely agree with Kris and BluErf. These blades are continually being repaired and redressed and as long as it is done in the traditional style (or better yet within the same culture by their craftsmen using traditional methods) there is no loss of value or history only an increased esthetic. Who wouldn't want a complete blade with complete dress that showed the glory or the height of that culture in their collection as opposed to one with pieces missing.
I had Hajiri build me a new scabbard for my barong and rewrap the handle with silver braid, all the materials were from Sulu and he and his Grandfather did the work. It is a much more visually stunning blade now and better represents the true Tausug craftsmanship as opposed to the tail-less colored-ribbon wrapped scabbard it came in.
That doesn't negate my preference for an intact old piece, I just usually can't finance those
Dan