old Knowles pottery platter, hand-painted pattern sample piece

Interesting old pottery serving platter, vintage Knowles china with a floral pattern. This has been cold painted (painted decoration on top of, rather than under glaze) which is not usual to Knowles china.

We've bought and sold quite a lot of vintage Knowles china over the years, and have never seen this pattern before - the plate reverse is unusually marked, too, and we believe this was probably a pre-production sample piece, for Knowles or perhaps another company using Knowles blanks.

It came straight out of a farm estate in rural Illinois, but aside from that, we haven't been able to find out very much about this piece. We'd guess it's late 1940s or early 50s from the marking.

It's 13" long end to end, and in very nice condition without damage.