Large magazine artwork 1960s/70s, Paint on board, 'Shadow of a star'

A hand painted UK magazine artwork produced in the 1960s/70s for a story called Shadow of a Star'. It's paint on thick artboard. It has an oil-like appearance but possibly it could be something else (gouache with varnish?) It measures approx 27.5 x 19 inches.

My photos are a little out of focus unfortunately!

Although labelled as an illustration for part 6 of a serial I have previously found with Haseler's work that they sometimes make appearances as book/magazine covers despite this labelling (or are published more than once).