Purchased A Luger

[CamaroDMD]

Here are the inside of the grips. Are these anything original to the lower half of my gun or should I just replace them? If I should just replace them...does anyone suggest a dealer for walnut checkered grips?

I see a 21 stamped into the grip...that's the only number I see. I assume that's the serial and if so it does not match any part on this gun. I see other letters though.