Hi and welcome.
Thanks for posting an enlargeable image directly to the board - this is much appreciated, but we need to see a bit more than just the base (and the considerable wear on it), please.
We need to see that, of course, we love looking at bottoms here,
but an image of the whole plate on a plain white (or black) background would help greatly us to identify your piece, if we can.
You can put up to 4 images in each posting - just click on the bit under the Browse box which says (more attachments), and another Browse box will appear.