The article describes all the jokes and scenes and plot devices and much of the dialogue that would have been used had this been made into a full cartoon. The story begins with Popeye, Olive, and the nephews coming to Bluto's tourist attraction, a cavern. 

The nephews want to know how the cavern was formed and Popeye tells them. Through a flashback we learn that as Popeye and Olive once were on a skiing trip, The Devil (Bluto)
appeared and took Olive as his bride down into Hades. Popeye followed. He encounters an out-of-control burning elevator, a lava pit, little devils, an electric chair, and a Tabasco popsicle before finally losing a fight with The
Devil and being suspended over a pit of fire filled with devils and pitchforks. Spinach gives him ice-armor and his super breath freezes the cavern and turns The Devil into a large can of "Canned Heat". 

Back in the present, the nephews don't believe the story and give Popeye a hotfoot to prove he would have been burned. Then the nephews transform, through Popeye's eyes, into little devils. 

The character designs have Popeye in his blue uniform and Olive is Fleischeresque. Bluto, though, as himself and The Devil, is muscular, not flabby. 

The cartoon was probably scheduled somewhere between the war toons and MESS PRODUCTION. It has the wild, anything for a laugh, everything in constant motion, incidental characters popping in and out, and the Popeye muttering characteristics of the war cartoons ("Somebody must be talking about me. My ears are burning," he says at one point as the elevator car catches fire around him.) 

And it also has some of the romance FS became known for - Olive is chosen because she's "The  Prettiest of Ladies"; Olive lingers at the ticket gate because Bluto is flirting with her; The Devil's kiss turns her into melted butter and then she pulls herself together and grabs him and gives him an equally passionate kiss that makes him burst into flame; the two sit down to a romantic dinner together (but The Devil's choice of fare - logs, coal, and gasoline, and of dinner entertainment - a humanoid flame doing a striptease are too much for Olive); the wolfish villain pulls Olive close as she tries to escape and then chases her around his place (as he transforms into a blast furnace and a locomotive). 

As Tom Bertino, the author of the article, points out, censorship probably pulled the plug on this one. "The whole concept, and some of the specific dialogue and imagery would have been quite out-of-bounds in those days.  It's a shame: it would have been a great cartoon!!"