Hi Keith - I like the expression 'or maybe someone else'

this is presumably a 'pressed' piece - were Richardson known for pressed pieces - do you have some particular reason for thinking of Richardson? Sorry, I really can't offer anything constructive, other than suggesting had you considered possibly Stuart or Davidson??
I seem to recall that Davidson might have done some vaguely similar pieces, though have to say can't now remember if this particular shade of green was something they did.
Hope someone comes up trumps for you. Nice piece by the way.