Mempo dating

[GN174]

Now I have ordered in lots of books on the basis of expanding my knowledge base, on the Mempo I can see that there are distinct styles and designs that are attributed to some of the highly regarded armourers. However I can't see that there is a style or design (beyond a specific armourer) that would link a particular Mempo to a date range other than some of the very early pieces. Are there stylistics features and designs that were only introduced after a certain period. I have attached the image of the one I have as I have looked a 100's of examples and I can't place it. It is the Hana that is throwing me just the shape of it. Real or fake I have no idea? Any guidance as to rules of what to look for would be gratefully received, I am guess it is by way of building a mental encyclopedia of other works and referencing them.