Marvel Feature no.6 (vol 2) Sept 1976 with cover art by Frank Thorne.
This issue is the middle of a three-part story that started in Conan the Barbarian 66 and finished in Conan 67. Looking for a mercenary, Karanthes hires Red Sonja to help him find a lost page from the Book of Skelos. Conan and Belit have cameos.
The first run for Marvel Feature showcased the Defenders in 1972. The 1975-76 run highlighted Red Sonja for seven issues before the she-devil with a sword carved out her own book.
The cover is listed as Frank Thorne pencils and inks, but her face looks like it might have some John Romita Sr. work. JR and Gil Kane produced the cover art for the first issue, which I’ll probably post later this week.
Another footnote: this is only the second issue of Marvel Feature to have a barcode printed on the cover with the first one being issue 5 two months earlier for the bi-monthly title. The UPC code is in yellow. This didn’t happen too often over the course of 40 years of barcodes that were almost always white.
Frank Thorne drew monstrous creatures, amazing hair, great back dimples, sinister villains, and fiercely magnificent horses and all are on full display in this issue.