I know of no knife stores in DC that sell anything that you might be interested in. What you can buy is POS knives at Sunny's Surplus, that sort of thing. Once, there was a store that sold Randalls and such but that was back in the 1960s.
In Northern Virginia, you have Chesapeake Knife & Tool and the Remington stores in the malls. You can pretty much forget the Remington stores, as they have cut their knife selections way, way back to almost nothing. It's sad, as they used to have nice things at the one at Ballston. The CK&T stores tend to vary wildly with their staff. Some can be fun to visit and others can be a real pain, it all depends upon the personalities of the people who work there. If they are knife enthusiasts, the visit can be fun, but if they are the usual paid employees putting in time, forget it.
There is a Spyderco dealer down in Fredericksburg, VA, about 45 miles south of Washington, down I-95 towards Richmond. I forget the name, but you can find it on the Spydie website. They sell other knives as well and the couple of times that I have been in there, it was a fun visit. You can also visit the Fredericksbutg and Chancellorsville Civil War Battlefields, if that interests you. They are quite interesting, and Princess Caroline Street in downtown Fredericksburg is a nice place to visit for a day's browsing and shopping. Try out Goolrick's Drug Store, they have a soda fountain just like I remember hanging out at in the mid-1950s, except that they don't have a revolving stand of comic books.
