I read a post a few weeks back of some people trying their hand at casting parts, and were looking for bits to cast/make plastic copies of.
Since ninja swords are so darn hard to find (and everyone needs one for their Deadpool, etc.):
If I can get the original back, I'd love to loan out the katana ninja sword that came with my Ninja Gaiden figure. It's 6" scale, and I (and others) would greatly benefit form having casted copies made available.
I'd offer to but I haven't done a 2 part mold yet and I think that's what this would call for. You might be able to do a one part but you'd risk either the mold or the blade during demolding because of the guard.