This issue has variants.
coloring credits acknowledged by Barry Windsor-Smith in Spectrum Super Special #3 
Inspired by Robert E Howard story 'The Black Stone'. Smith credit changed from sketches to layout, based on splash page credits and info derived from letters pages.
According to the interview of Craig Russell in Conan: The Jewels of Gwahlur, only the first page and a couple of separate panels were fully drawn by Barry Smith, Val Mayerik completed figure work and Russell backgrounds. Inker Dan Adkins fell behind and called on them to do finished inks.