I would like to find out the name of the manufacturer who stamped their vintage (approx 1970's) sterling silver jewelry rings with "Sterling B"...and the letter B has an A inside the top part of the B and an R inside the bottom part of the B. I've seen this hallmark only on sterling silver rings that have a faceted glass stone. Esposito (ESPO) and Vargas made similar rings.
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Thank you for any help.

