Please allow me to add a "local note" to this discussion of Kofun era blades. It involves a sword that has a bit of history - and some hard feelings - that happens to have ended up in my collection. I bought it some years ago at Tampa where it was being sold by a well known collector for the fellow who had bought it from
a GI who got it in Japan.
Here's the sword
The fellow who acquired the sword did enough research to decide that it was a "warabiteto". He showed it to a serious dealer who agreed that it looked old and potentially valuable. The owner had the blade polished by a state-side polisher and proudly reported this fact to the dealer. The dealer suggested that the owner was despolier of an important cultural icon and that it was now worthless. Further harsh words and emotions may have been involved.
Still convinced that he had a good object, the owner sent it to the NBTHK for assessment. After waiting a year he wrote a letter inquiring about it. In response he got a card saying that the blade was outside the expertise of staff in Yoyogi but that it would be brought to Nara for assessment by an archaeologist. After another year, the owner made another inquiry. At that point it was returned with another card suggesting that the sword was a Meiji-era weapon.
It was at that point that the blade showed up at Tampa waiting for me to walk by. I had seen some warabiteto in Tohoku. The distinctive feature of those swords is an integral hilt shaped like an unfolding fern. This blade has a spikey nakago with a single mekugi-and a jiri that looks like it may have been peened on to a pommel. That design is what the folks at Yoyogi saw as evidence that had been put into some manner of gunto koshirae. After I bought it, a well-known Japanese dealer made a play for it, but I hung on to it like a new toy.
This is not a warabiteto, but it looks very old. The rust on the nakago is ancient. I never saw the unpolished blade but there seems to have been some serious pitting. Still, it is healthy. The hada is truly coarse but the shape – a sort of long kissaki moroha hira-zukuri – is well formed. And there is a well controlled flowing suguha hamon.
This sword sure looks like the sort of weapons that were being produced before the Heian era, but there is little more that I can say