It looks like a commemorative keyholder, possibly from a miniature car (70th anniversary?). The key has a sterling silver hallmark, but the material is unknown as it hasn't been appraised. The Mitsubishi one doesn't appear to be silver, judging by the color. Together, they weigh about 18g. Individually, I think it's about 11g. No claims, no returns. Please confirm before purchasing, as these are used items.