On the subject of blade style, maybe the smith decided to have a change, try something new, maybe he felt a bit exuberant that day and decided to copy a blade that he had seen for a change, on the subject of bad mei, perhaps he was an alcoholic and had hit the saki to hard before signing it , perhaps he was ill or simply he felt the blade wasnt upto standard and got his apprentice to sign it for him. We are only human, not robots, forgive my naiveness, and feel free to correct me?
Alex.