Wagner,

Thanks for locating those images - I was rooting through my own material, trying to find something similar - but you have done it better for me, especially as it comes from a respected, published source.

I will try and combine two of the images, to save viewers the problem of scrolling back and forth over the two pages.

Thanks again for your help.

FJS

Two_silver_marks.jpg (53.02 KB, 801 downloads)