Pistol grip and semi pistol grip (PoW) stocks on german guns

[Shane Thomas]

About when did they first appear? Did they start to appear on Germanic guns at the very end of the percussion era or was it well into the breech loading era?

On British guns I've seen a few percussion guns with full blown pistol grip stocks but never a German.

Any pictures or links to pistol gripped, German muzzleloading guns would be greatly appreciated