I have a squash Blossom that has a Hallmark with a backward R attached to an A the letters are in Caps. The two letters are Back to back but attached to each other (combined to make one separate image. Can you identify?
According to Hallmarks of the Southwest by Barton Wright, that hallmark belongs to Navajo silversmith Roy Anderson Jr. who worked for White Hogan. His father was Roy Anderson and his sister is Evelyn Anderson.
Perhaps others have more to add about this artist.