What a great find! May I ask which shop? From the serial number list at http://www.antiquecameras.net/petzvallens.html, it looks like it dates to 1849. You've got some luck on your side, I hardly ever see any CC Harrison lenses for sale these days--let alone such an early one. It's a Petzval portrait lens that would likely have been used for shooting up to half-plate size.