Thanks to Jeff and the Grand Grognard

"In future, I plan to be a lot more circumspect, perhaps even going so far as to adopt Jeff Rients's suggestion (a link to which I can no longer find) that each magic item in the D&D rulebook is unique -- if you find a sword +1, you find the sword +1 and no one else will ever possess one unless they pry it out of your cold, dead hands."