Brandenburg, Germany. I would be willing to bet that it was reconverted. When it was converted to cap is probably when the checkering was added. The patchbox lid may be original, but has had the dome taken down and checkered, also probably when it was refurbished. I have seen quite a few of these earlier German guns that had been checkered like this and I'm guessing they had make-overs at the same time as their conversions. The Euro conversions weren't simply done by screwing a drum into the side of the barrel but rather they would cut off the breech end of the barrel and add an entire new plug set up. Very strong, but also ugly, imho. These early German guns might appear to be clunky, but most of them are much more petite, lighter, and better handling than then you would think.