Any idea who made it ?

Hi any idea who made it and how old is it

If you can get a better picture of the Lozenge mark or read the characters
at the 4 corners, we can date the design, it's certainly before 1884.

The blue star mark looks like a Minton cypher for 1842 sometimes impressed or stamped, the diamond registration mark was also first used from 1842, it's a possibility made by Minton.

Any trick to read the diamond as its very hard to work out the numbers letrers