I did manage to dig up my copy of Marvel's Savage Sword of Conan #19 and read Don Glut's adaptation and completion of Robert E. Howard's Solomon Kane fragment The Castle of the Devil. Glut's version gets off to a slightly different start as the person Kane rescues from the gallows is a nubile and nude young lady as opposed to the young boy of the prose version. Aside from that, the events and dialogue stay true to REH right up until the final line of the fragment. After that, Glut takes us into his own brand of horror tale. Glut's Baron Von Staler, the titular devil, was born deformed, having the lower body of a goat so that he does bear a resemblance to old scratch. He's made a pact however with the real devil, who, for the requisite number of sacrificial virgins, will cure the Baron's deformity, making him entirely human. Solomon Kane and his newly met ally John Silence show up in time to save the most recent virgin. The baron isn't about to let his chance to be human escape though and much bloodshed ensues.
I enjoyed Glut's version of Castle quite a bit. I've long been a fan of Glut's Gold Key heroes Dagar the Invincible and Dr. Spektor, a barbarian warrior and an occult detective respectively. In Glut's take on Kane we get a little of both heroes as the sword wielding Kane steps firmly into Spektor's stomping grounds. There are some fun gothic overtones in the dark castle and Glut works in references to Dracula and Frankenstein. A few issues of Savage Sword later, Kane will have an adventure at Castle Frankenstein in fact. Glut has a long history of writing tales about the Frankenstein monster both in comics and in prose.
For more about Don Glut, check out an interview I did with him a few years back. The link should be at the bottom of this post. I enjoyed talking to Glut and he said I'd made his day when I told him that as a child I actually played at being Dr. Spektor in my back yard, fighting mummies and vampires and the like. I was apparently the first person who'd ever told him that.