Royal Doulton .....art pottery ID please!

Hi,
I have this Royal Doulton dish that I’d love to find out more about!
I haven’t been able to find out anything using Google!
It has a very art pottery appearance (IMHO) as it has a quite thick glaze and is hand painted in deep red, blue and earth tones .
The Royal Doulton mark is a bit blurry ( I think it is under the glaze) and is marked 8156 and 4.39
These numbers are not impressed but appear to have been incised by hand .
At a total guess I think this points to an April 1939 manufacture date but I’m more intrigued by why I can’t find anything similar on the net?
Could this be a trial piece?
As usual, I’d be very grateful for any info!
Thanks.

This version of the mark was used from c1930, but without a pattern name,
or Rd number, it may not be possible to find more info.

8156 could be the pattern code. Nice unususal item anyway.

Thanks for the info denbydump!
I’ve not come across a piece of Royal Doulton before that looked , for want of a better word , rustic ,but this does appear to be so (IMHO anyway).
The hand painting and the incised lines inside the dish all contribute to giving the item a feel that it wasn’t churned out on a production line , hence my idea that it could be a trial piece.
I guess I may never know , but I shall certainly continue looking.