EUC copper twisted bangle bracelet

EUC copper twisted bangle bracelet C. 1970s. I wore it some and somehow knocked it up a bit. It’s a bit bent. I don’t know how to clean it. In storage it darkened. I just wiped the dust off but didn’t polish it. Even though I bent it, it’s quite solid and heavy for the dainty width. Group photo shows the variety in the collection