Recommendation for buyer of estate jewelry

Can someone recommend a place or person that buys estate jewelry? A
customer has a pair of 18KT gold and diamond earrings that she says
wants to sell and put towards a new car. They appear to be from the
1960’s and are huge, leaf shaped things ringed with about 1.6
carats of high quality diamonds. (appear to be G color, VS2)

Thanks.
Diana Widman
Birch Tree Studio Jewelry Designs
825 South Waukegan Road A8 #184
Lake Forest, IL 60045
847-235-1686