I will attempt to maintain a list of weapon rack locations. Please message me or reply to this thread with new locations / updates.
These are possible places you *could* scavenge a katana or zanbato
2xSaotome School (inside) (17,74)
Wong Fei Hong Library (inside) (59,64)
2xKung Fu Dojo (inside) (34,60)
Martial Arts store (inside) (35,63)