Before I go crazy..... Does anybody recognize this pattern? or marks?

I am not sure I know anything much about this plate at all. It was among several dishes either at an auction or sale of some sort
I believe it is very old because of the look and feel of the plate but I have not been able to identify the incised mark - some times I think it looks like a horse, but then no, is it a shield? There is also the number 10 incised on the plate. The crown is just a crown.... no letters - at least nothing I can identify. I have tried searching so many combinations but so far I have not been able to find anything at all. Please help me if you can!