You definitely need a spacer I'd say as all of the braces I've had for Judy forks, standard or after market, all have something that adds distance from the brace, whether in built or extra as per the pics others have posted. Obviously each brace might be slightly thicker/thinner than others but all will have been designed to work with the original boss bolts. I'd try an get a few measurements from others of the total depth of the brace and 'spacer' and as you don't need the holes for the brake springs, try and find something that achieves the right measurements whilst fitting over the bolt. Might a chain ring spacer work?