Hello I am new to this group and could use some help in Identifying a Shirasaya sword I bought at auction . it has not been well taken care of the scaber and handle are taped together , the sword is not rusted but does have some flaws to it the tang is rusted . I can not find a makers mark on the blade. the blade does not show signs of being sharpened, but it is very sharp. when assembled the handle and scaber match perfectly. How do I determine the age of the sword and authenticity of the sword. Any help would be appreciated.