John Plimpton assembled an incredible collection of Japanese civil, government, diplomatic, and Imperial swords, easily among the best of such items anywhere on earth. 3 friends and I have purchased the collection and are in the midst of dispersing it to new owners. 11 fine pieces (those pictured and others) will be sold on the 27th of April, 2022 at Cowan’s Auctions. See lots 156 to 166 of the sale here:

https://www.cowanauctions.com/auction/4272022-arms-armor-13005

Mr. Plimpton collected the best of the best; many of the pieces are exceptional for their rarity and pristine conditions. The collection is set to be published in the upcoming book A Guide to the Identification of Imperial Japanese Swords, 1873–1945, which should be spectacular.

These swords aren’t for sale from my site; you have to go to Cowan’s. It should be well worth the effort.