I *love* my Brigham -- an old "one dot" very similar to yours -- mine's in a dublin/pear shape, about the same size and a 1/4 bent, but yours is rusticated and mine's sandblasted.
Brigham is the only pipe I use the filters in. Only the Rock Maple Brigham filters fit a Brigham pipe. One filter comes with the pipe and extra filters are sold in boxes of 8 filters for about $3. Sounds expensive, but one filter lasts through 20-30 bowlfuls -- just rinse the filter and the stem under hot water and use pipes cleaners on those after every smoke.
Brigham filters can be hard to find at local B&Ms that don't sell Brigham pipes, so be sure to toss a couple 8-packs in when you buy your new Brigham or include the filters in your next online tobacco order.