I just measured mine and they differ from Pipe clays a little.
They are 184 mm round and 12mm thick with 3.25mm holes that are 4.2mm deep.
1 plate has
one side--other side
99----------97
93----------91
88----------87
83----------81
79----------77
73----------71
69----------67
63----------61
2nd plate
59----------57
53----------51
49----------47
46----------44
43----------41
39----------38
37----------34
32----------30
28----------26
When your ready I can put up a detailed drawing of the sector arms etc, if you need it.

Dave