The same key locks our Yamaha grands and our Young Chang grands. Are Yamaha keys easier to source than Young Chang?
They're the common Asian style key, available from Schaff and Pianotek.
I have just about every key for all mfg's. What's interesting about the difference between the YC and yamaha key is that the yamaha key will work in the YC. But the YC won't work in the yamaha. Because of the tang and end hole.