This is from 'Catalogue of a loan exhibition of Japanese sword fittings held at the Metropolitan Museum of Art, New York City, August 1 to December 31, 1922'
INTRODUCTION: A SUMPTUOUSLY illustrated folio volume by John Ogilby was published in London in 1670, made up of English translations of collected journals and reports of embassies from the Dutch East India Company to the "Emperor of Japan"— presumably the reigning Tokugawa Shogun, to whom the Dutch paid annual tribute as part of the price for the exclusive privilege of trading with the Japanese. In the early part of the book extensive quotations are made from "a good author, Johannes Petrus Masseus." Among the characteristics of the Japanese observed and noted down by this good author are these: "They much delight in war; Their arms, besides Guns, Bows and Arrows, are Faulchions and Daggers, which they begin to wear and exercise at twelve years of age ! Their Faulchions or Scimeters are so well wrought and excellently temper'd, that they will cut our European Blades asunder, like Flags or Rushes, the edge being neither rebated nor notch'd. "They also have javelins tipt with gold or silver and their Pikes, which are longer but lighter than ours, they know how to handle dexterously." "They also set a strange rate upon Sword-hilts, especially when made by some peculiar masters."
As this publication dates from only 19 years after the English Civil War it would seem reasonable that the English knew of the quality of Japanese weaponry from both the Dutch and Spanish traders who were dealing in Japanese swords at least, since 1600, as the 'San Diego' wreck would prove https://tsubakansho.com/tag/ship/ And it is also likely that, as now, weapon traders find a ready trade in times of war. Those traded swords would find a ready market in Europe in the 17th century.
And not only Europe it would seem from: 'American Anthropologist' by Bishop, C. W. 1917-01-01
"A piece of evidence of Japanese relations with Indo-China is presented by a Japanese sword guard found at Angkor Vat." [Wat]
The KHMER kingdom spanned the years 802 CE to 1431, Angkor Wat as its capital. So the Japanese were trading weapons as far back as the 15th century.