The black one that specifically says Pickett on it, as seen above in the picture, will spread to a 180 degree and as measured, would work for a full 10 inch radius.
The larger of the other two, as seen the pictures above, would make a 5 5/8 inch circle.
The smaller of the three, as seen in the pictures above, would make a 1 6/8 inch circle.
The smaller compass is missing its end caps on the bar in the middle that adjusts the radius. However, with great force put to the turning wheel, it will not cause the bar to separate from the compass! Meaning with these two missing parts, it does not effect the compass!