It took me quite a while to parse the map properly, but this is a very reasonable dungeon crawl with some interesting ideas.

I will say that I was a bit disappointed about the use of the title. Knowing Ogun from being an orixá in Yorubá religion and in afro religions in Brazil, I was initially excited about a Ogun Dragonslayer, and it got me wanting to see more ties to the god of war and metal, with maybe some African-inspired themes, thinking the offal maybe being some kind of offering. I guess that’s on me for coming in loaded with expectations, but it is a bit sad that the module doesn’t use the full potential of the name to reinforce the themes.

This one has a lot of potential, the prose is strong (albeit purple at times, but I think that is in-keeping with pulp fiction) and the locations described are right at home in Appendix N, additionally the two maps you have provided are simple but effective (side-views are always a fun touch). The implied setting is interesting, but given how many words there are I'd have liked some more concrete context for why this stuff is here, beyond the vagaries of the hooks.

I understand what you were going for when the prose begins to blend with game content more: diagetic but gameable text is great, but it is hard to pull off and I am not sure it lands properly here. The module has strong writing from a technical standpoint but the flowery prose begins to hinder the delivery of information here. The keys could be a lot simpler and still retain their key information & purpose.

I think it largely comes down to presentation/layout: if columns, boxes, italics/text-emphasis was used this would be a lot easier to parse and allow it to shine even more.

This is an interesting one though, some more editing and polishing and it could be a satisfying location to include in a game!

Very well written but wordy, and for me quite hard to pace and get into. On point with S&S prose.

Reading this felt like reading a location description from a bona fide Appendix N novel or story. The vocabulary, the cadence, and even the finer details all evoked the feel of low fantasy story for me. Even a sentence that is explicitly breaking the fourth wall and talking to the adventure reader like "In these pages our concern is with the first cave, a former mine, and its outbuildings." would not be out of place in a story out of Weird Tales. Love the overworld description. The dungeon has pretty precise details, but I'm not smart enough to get it all on a first read through. I would need some legwork (and a dictionary) to understand the finer details. Good work.

A few favorite things:

• Great vocab for the verisimilitude of the natural and mine environs
  
• The tiered irritable and stunned effects of the flooded winze
• The three opening rumors to get things going

I would echo much of @HogwartsHoe's feedback. But good work!

The first two pages are really well written and evocative, but I'm not sure they're the best way to communicate for playability. I think I see what you're going for, narrating in prose what someone would encounter if they were making this trip. I can see how a GM might translate that into a playable experience, but I think it'd be a little bit of an extra challenge. Personally, I'd be tempted to just lift the whole thing as a travel monologue, omitting the encounters and rewards. 

The second two pages are closer to what I'd expect from a typical dungeon module in presentation. I'd recommend maybe combining the two pages into a spread, so you can see both the schematics of the dungeon and the location descriptions on the same page. 

I think you have a good voice for creating dungeons, you nail the tone. I'd just try to focus on considering, "How will someone play this module" while you're writing and I think you'll be able to make the conversion between writing a short story and writing an adventure module. If you're looking for some specific recommendations:

• Try to incorporate headers that flow into each other. That will also help with someone referencing the document as they're playing it if needed
• Find a way to separate the prose, which can be used by the GM while describing a location, from the meat of the adventure (encounters, rewards, etc.)
• Break up your document into two clear sections: travelling to the dungeon and arriving at the dungeon. You could also consider doing two A4 spreads for ease of reference between the two
• If you'd like to keep the prose and use it as an adventure intro, that's also totally fine. I'd just try to cut it down to the most important bits and then use the rest to help communicate how to travel to the dungeon and what an adventuring party might encounter along the way. 

Lastly, I think you have the tone and theme down, but I do think there's some follow up missing with the connection to your title. I've read through your document twice and here are the connections I think I understand between the content and the title:

1. The journey described on the first two pages was undertaken by an avatar of Ogun who carried holy weaponry. The players are following in their footsteps as they undertake the same journey for unclear reasons.
2. The mine on pages 3 and 4 have some connection to Ogun, likely a worship place as it includes an altar
3. Some magical weaponry can be found in The Old Lair, it's unclear if this weaponry is the same as was carried by the Avatar of Ogun. Some unexplainably immaculate armor is also in this lair. I assume Ogun's avatar brought this stuff here and then left it. 

I think being a little more explicit in how this area connects to Ogun and his offal would help put a bow on the module.

Cool, terse adventure. Very old-school vibe.