More than one Invisibility cloak......?

According to the legend or rather the true events based on the invention of three most powerful magical objects by Peverrel brothers namely, Elrond wand or wand of destiny or deathstick, ressurection stone & the invisibility cloak must exist in singular number each. Well, that is more likely, because It didn't sound from the stories in the "The tales of Beedle the bard" that those brothers made those objects more than one each & in later generation of witches & wizards only Dumbledore & Grindelwald actually understood the meaning behind the fairy tales & tried to unite the three HALLOWS. But in "Harry Potter & the Goblet of fire" we have found that Barty Crouch had an invisibility cloak. How's it possible? was that a true invisibility cloak or just an ordinary ones? It also isn't likely that Barty crouch just took chance with an ordinary cloak, enwrapped with some temporary vanishing or invisible enchanment. Because except the true one like Potter's the charm is bound to be faded off after certain period of time. This is so unlike of Barty Crouch that he depended just on a single temporary & a bit frail thing with his most important things i.e. pride, prejudice & his position in the ministry. Also in first book i.e. "Harry Potter & the philosopher's stone" Ron mentioned then as rare not as the single most thing existing in the world. That indicates there are more than one, but I guess he reffred to the ordinary ones. So if Barty's cloack is a true invisibility cloak, he too bound to be the descendant of Ignotous Peverrel & related to Potters. But more than 1 invisibility & Barty using an ordinary invisibility cloak, both seems improbable.