Hi Debs - -
Sorry none of us have been able to properly identify your gorgeous plate on a couple of web forums - I did think of one thing that might help since the X ? mark is so tiny - I have read of others sprinkling cinnamon over the impressed mark and carefully brushing away the excess - It might bring it into sharper focus for a camera but at least for your own identification even with a magnifying glass - and it won't harm or mark your plate - KB