I was never a fan of the dinosaur story arc so this cover doesn't really appeal to me, in fact I find it silly (and not in the good Archer & Armstrong way). Despite that I love me so Barry Windsor-Smith on Valiant action.
For comparison, here's the published cover.
UPDATE: Found that this page is available for purchase directly from Barry Windsor-Smith himself for a cool $3,000. According to the site, it is the only Barry Windsor-Smith Archer & Armstrong cover original art to ever be offered for sale.