Most assuredly not a waste of time! I didn't have any context for the english on the back either, so your commentary honestly helped a lot. I didn't know what 3000 yen meant, i.e. does it mean the value of the sword, the cost, etc. We had no idea where it came from, espeically that it might have been purchased from a pawn shop. Thank you again for your help! This is very interesting!
Also, I will see what I can do about pictures of the sword handle, I'm very interested to see what it means.