VTG I Our Engagement I Diamond Ring I Pendant

This is either a very large charm, or more likely a pendant, by M&M Sterling. Base is a large, shiny diamond shape w/a "hemmed" border on front & back. On top of diamond is what looks like a little round table (w/3 "legs"), or circle, w/its own distinct border & carved out center, serving as a platform for the pièce de résistance, the "diamond" ring! Top of the circle reads "OUR ENGAGEMENT" & bottom has 2 shiny strips separated by shiny heart. Shows some wear, pictured. Measurements photos 6-8.