We have 6 sets of clamps without screws. They are a thicker heavier clamp than what comes with our sheaves.
whizzercruzzerparts.com
You can ask Paul if he will sell ya just one But I kinda doubt it, no one likes to break up a set
Your just gonna have to bite the bullet and spend the $28
Unless ya think you can fabricate a bracket yourself
If your not too picky about missing one bracket
Basically all's ya need is a screw,nut and a washer to secure the sheave to the spoke
Kinda bend the washer so it lips over the spoke