Narrowed 8 3/4 questions

Got this from Oldkimmer a few years ago and may have seen 72bluNblu post it once. turn backing plate on axle side on flat table. knot on bp has to hang off table. measure from table to center hole. measurements as follows.
1 1/2 inches are 11x2
1 3/4 inches is 11x2 1/2
2 inches is 11x3
thinking 72bluNblu said 11 bp are 12 inches in diameter and 10 inch bp are 10 7/8 diameter.