I've seen illustrations (...old Edo prints) of samurai from around 1300 (since wakizashi did not yet exist) who, with their armor, carried a sword and a tanto dagger, which I presume was a sunnobi-tanto, that is, longer than usual.
My curiosity was drawn to the hilt of these daggers, which often featured a white sawagane without a "tsuka-ito" but with a wide tsuba. These are symbolic illustrations, or perhaps they were worn like this in Muromachi?
I'm interested in this because I'm preparing a hilt for my 14th-century sunnobi tanto and am unsure whether to make it with or without a wide 7 cm diameter tsuba (since the hilt, without a tsuka-ito, is made only of ray skin and decorated with two large menuki).