You might try their website:
http://www.grullaarmas.com/es/ I bought a 216 rounded body a couple of years ago and have been delighted. I decided on Grulla after going to the shop of each of the gunmakers in Eibar and Elgoeibar (sp?) and found Grulla's to be the best handling. Arrizabalaga is best for fit and finish, but their guns are heavily built, for driven shooting, and so are not a good match for U.S. "rough" shooting.
I used a patterning board on my gun and found both barrels precisely regulated to shoot to point of aim. Surprised GSI considers 5" low to be "within spec." Suggest you communicate directly with Grulla via their website and relay this story. I found them to be proud of the quality of their guns and willing to stand behind their product.
