kind of percussion instrument, clamp
鍄 centers on a metal object used for holding or striking: a clamp or a kind of percussion instrument. Both senses share the idea of a metal tool that applies pressure or impact.
鍄 combines the metal radical 金 with the phonetic component 京. The exact historical origin is uncertain, but it likely follows the common pattern of using 金 for metal objects and 京 for sound.
The left side 金 means metal. The right side 京 looks like a tall structure. Imagine a metal clamp holding a tall metal percussion instrument in place, ready to be struck.
For リョウ, picture a metal clamp holding a 両 (りょう, both) ends of a percussion instrument together: 両 -> リョウ, and the metal clamp secures both sides.