Hi Tam the technique of producing a relief decoration by punching or hammering the metal from the back in order to raise the design on the front is called REPOUSSE.
The technique is done by hand punches and hammers or sometimes by mechanical means. Sometimes in imitation of repousse work, the design is not beaten from the reverse but pieces of metal are soldered to the front to achieve the "raised up" look.
A Cameo has the "raised up" look you correctly identified but is carved into the material from the front. Originally colored gemstones having layers of different colors were used for making cameo to show in low relief the design and background contrasting colors. In later periods, cameos were carved in other hard materials, such as rock, crystal, coral, jet, shell etc.
Without seeing a photo of this item and the lady on the front and other little tell-tales clues we may find, it's basically impossible to date.
Sorry Tam, but we do not offer a send in photo type service at this present time.
