The Magonium Mine Murders: system stuff

Another update on my ongoing plan to turn my scenario, The Magonium Mine Murders, from note form into a product a DM could use to run it.

One thing I haven't talked about is system. The obvious thing to do is use the extension of the OGL to 5th edition to write it for 5th, which, after all, is the system I'm currently using to run the game. 

This has obvious advantages: first, it's a popular system and one I'm reasonably familiar with. The scenario will include a couple of monsters, some magic items and so on, which gives 5th ed. DMs some crunchy bits to play with in a field where that's still a pretty valuable thing. 

The bad news is that I am not a systems guy, on the whole. One of the things I like about the OSR (and the Oldhammer movement, come to that) is that the loosey-goosey attitude to rules means that concept is more important than implementation. But I feel like if I'm going to be selling something, I can't just half-ass it, which is 100% what I would normally do in my campaign. 

The alternative, I suppose, would be to do it systemless or based on some kind of OSR consensus (systemless like most One-Page Dungeons, or Gormand's Larder, or loose consensus like Maze of the Blue Medusa). But while I think that might be easy, it feels phony. It isn't ... my native language, so to speak. And I feel like the scenario is probably 90% system-independent, anyway. 

I do feel like the language of 5th edition is easier to speak for me. Here's the stat block for a Mole Man, for instance.

Incautious adventurers trespass upon the territory of the Mole Men!

Mole Man

Medium humanoid (mole man), lawful neutral

Armour Class 13 (natural armour)
Hit Points 13 (2d8 + 4)
Speed 30 ft., Burrow 30 ft.

Str 14 (+2) Dex 12 (+1) Con 14 (+2) Int 11 (+0) Wis 16 (+3) Cha 10 (+0)

Skills  Nature +2
Senses Darkvision 60 ft., Tremorsense 60 ft., passive Perception 13
Languages Subterran
Challenge 1/2 (100 XP)

Light sensitivity. Mole Men have disadvantage on all saving throws, perception checks and attack rolls while in sunlight or similarly bright light.

Surprise attack. Mole Men have advantage on attack rolls in a turn in which they emerge from a burrowing move.

Actions

Claw. Melee Weapon. Attack: +4 to hit, reach 5 ft., one target. Hit: 6 (1d6+2) slashing damage.

I think that's about right, although it doesn't reflect the fact that Mole Men use a variety of weapons.

Now, I don't quite know the ropes with the 5e SRD and the OGL and whatnot, but half of this is about teaching myself things. Of course, that's going to be rather more difficult with design and layout, which I did briefly do for a living, but ... that was in 1999. 

I suspect what I will do is draft the thing and then bounce it off someone who knows more of the system than I do. I do have scruples about the extent to which I'm relying on the unpaid help of others, but that's a post for another time.