Chris-
In the late Muromachi blade shapes like this, moroha-zukuri, shobu-zukuri, kanmuri-otoshi and others became popular. Short stout tanto made for use as armor-piercers from that era could all generally be called yoroi-doshi which means "armor-piercer". Double thick hira-zukuri blades are most often described as such.
They again become popular in the late-Edo period. I would study the shapes of dated examples from both eras and draw your own conclusions...
A nice little piece BTW
-t