Stoneware plates no makers mark

Hello - first time posting!
I recently bought a set of 6 plates from a local charity shop and would love to know if anyone can ID the maker please. They are quite heavy like ironstone, and each has a different design although I'm pretty sure they are all the same brand.  Most have got some writing and / or numbers on the back - I wonder if they were sample glaze pieces? They measure approx 8 inches across
Thanks!

Lovely dishes, especially the one in the middle. Yes, they are glaze codes and such items rarely have the potters stamp so difficult to ID. Blythe might be their name

They look moulded so possibly production ware.

Yes the one in the middle is my favourite too!
Hopefully someone can help solve the mystery

It looks like Blythe Colours and Meirswann (written on the grey plate) were suppliers of colours to the pottery industry. Blythe later operated as Johnson Matthey.

https://draycottinmoors.wordpress.com/2020/09/15/175-years-of-colour-making/
https://webcache.googleusercontent.com/search?q=cache:J2QLCvDumHEJ:https://potteries.staffspasttrack.org.uk/Details.aspx%3F%26ResourceID%3D35366%26PageIndex%3D2%26SearchType%3D2%26ThemeID%3D237+&cd=3&hl=en&ct=clnk&gl=uk

Wow that's fascinating to read about, thank you! So much industry and expertise lost forever.  I am going to contact the Blythe memories group to see if anyone recognises them  

They might well have been produced locally to where you bought them, as it is the kind of thing that workers would be able to buy cheaply from the factory shop back in the day.