Re; the platter.
In order to pinpoint the maker and help you out, could I possibly ask for just two good photo's?
Namely, just on whole one of the front and the back.
On the site, you have many very good mutiples of the front, but not of the back, which is split into left or right hand views.
I strongly suspect this object of originating here the Netherlands, it might be either Delft or Maastricht wares.
You may post it to this site, or to the following; dlombardo@lifestyleantiquesforumandcollectables.com.
Yours etc...DL