Vintage Costume Jewelry (Cumberland)

Any condition. I am repairing old jewelry with missing stones, clasps and pieces.
I want to keep the pieces as authentic as possible using the closest to original as possible. Anything that can't be repaired will be reinvented into a new piece.
I am looking especially for any older pieces from Trifari, Coro, Van Dell, Weiss, Sara Coventry, Miriam Haskell. Monet, Eisenberg etc. Most of these makers may have the specific pieces I am looking for although I won't refuse anything as long as the pieces are from the 1970s or older.