This Simpkin, Marshall, Hamilton, Kent & Co. edition was “written and embellished” by Bernard Way and features what looks to be the first edition of the text. It’s a simple copy, but the poetry is quite pretty. The cover is purplish. It is undated, but it is possibly from 1919 or around then due to an inscription dated 1919.
This page on the Royal Academy of Arts talks about the publisher a bit.