Neither of the following novels from the collection of yours truly includes a cover credit, and if the art was signed by the artist, the signature has been cropped out by the designer; nonetheless, it seems likely to me that the artist is Joseph Lombardero, whose Sax Rohmer covers were featured here at RCN back in May of this year:
[CLICK IMAGES TO ENLARGE]
ABOVE: Neal Bell, Gone to be Snakes Now (NY: Popular Library, c.1974), with cover art by Joseph Lombardero (attrib.).
ABOVE: Poul Anderson, The Worlds of Poul Anderson (NY: Ace, c.1974), with cover art by Joseph Lombardero (attrib.).
ABOVE: Poul Anderson, The Worlds of Poul Anderson (NY: Ace, c.1974), with cover art by Joseph Lombardero (attrib.).
As always, if you think/know that I’ve made an attribution error, I welcome your corrections in the comments.