The big cog, courtesy [MENTION=172428]photogravity[/MENTION] , is a Sturmey-Archer (modern for narrow chain) 24T; and the small cog is a Shimano cassette cog 14T with the extra splines ground off according Sheldon Brown's recipe.



The anti-rotation washers are a S-A part available through Harris Cyclery. The S-A axle is narrower than modern dropouts; the washers make up the difference. Sturmey-Archer Axle Washer w/9.5 mm tabs HMW494 - Harris Cyclery bicycle shop - West Newton, Massachusetts