Hi John,

Subject to cold fingers, the plates measure as follows:

Dia 6and 3/8th inches, thickness 1/4 inch, centre hole 5/8 inch, index holes 1/8 inch, fixing holes 5/32 inch on a PCD of 61/64 inch. Holes are all "clear" measurements.

Index holes are countersunk both sides, fixing holes are well countersunk to sink fixing screw heads, centre hole not csk.

On each plate there is one line of index holes in line from edge to one of the fixing holes, these are numbered with the divisions, and are what you might call the "top" of the plate. In line with these is another hole 1/4 inch dia and about 2 inch in from edge, whose purpose seems to be to indicate the numbered holes.

Hope this helps – no doubt we will find out if I have mis-measured!

Phil

John,

Have emailed an image to you. PM me if it doesn't arrive.

Phil

I included a rule so that you could get it to scale correctly if you thought of using it like that. Given the problem of lighting flat steel surfaces for photography I think it is probably superior to a photo.

Phil