Vintage Siam Sterling Silver Nielloware Flip Ring

This double-sided "flip" ring has Nang Fa, Fairy of Happiness who is depicted as a Thai dancer. The other side is Thephanom, a Thai guardian angel deity. On another website, it said that Thephanom is a god of Welcome. Front of ring measures approx. 14mm x 12mm. Approx. size 3.5. On the interior of the ring, it's marked Sterling on one side and Made in Siam on the other. Based on my research, this dates the ring from the 1940s. Some marks on enamel, but flips effortlessly!