Copeland Spode

I have a set of 8 of these Spode Copleand dinner size plates. Each has a different bird in the center. Each has a Y mark on the back followed by numbers and a letter.
The marks are Y6046 P, Y6046 i, Y 6046 E

There are also some impressed marks, which I believe are date marks
N 87, D 87, A 88. I think these marks indicate the plates were made in 1987 & 1988.

I can't find any info on this pattern & would love to know any info about them.