Trachtendiele on Ballindamm, I just remembered. I think it's quite a nice shop. I have not been there for some years, but I think it's probably the best in Hamburg.

There used to be a great hunting store at the Gänsemarkt called Kettner, which sadly closed. They had a great selection; I bought my Barbour jacket there in 1989 and still wear it today.

Another idea that I forgot to mention earlier is Frankonia, a supplier of hunting clothing and equipment. I don't know if they have a shop in Hamburg. http://www.frankonia.de