Sorted!

Yeah, it is depressing to think how exciting Modron was when I first saw it in the late '70s, yet it's still one of just a tiny handful of fantasy RPG undersea adventures 40+ years on, for all the booklet doesn't really do as much with the marine environment as it might. That merfolk village layout is identical with what JG were doing for purely land villages at the time, for instance, albeit the seabed map is still the most detailed for any underwater fantasy setting, so far as I recall.

Thanks Julian.

The new FCW file shows one small grey patch still, on the northern edge of the map; it's Tag # is 248272, which should let you change its properties without having to find it first.

The latest update map image is looking good now. Just one bridge with odd shadows still, that between mesas 1 and 2, coming off the main eastern cliff-line.

So yes, with luck you can start adding actual map details next!

In case it may help Sue, you can find a moderate-res PNG of the seafloor map in the discussion on this blog from last April. The JG terrain symbols won't be much assistance, I fear, as they're the old dry-transfer rub-down-by-hand type (the map is from 1977, when this was state-of-the-art), but some of the information on it - and in the blog notes too - may be more useful.

The CD3 Bitmap B Elven style catalogue is essentially THE tree-settlement option. I think it should work just fine when converted to B&W, as the colour options have a good, clear range, and as it looks hand-drawn, it would be fine for OSR-simulations (we all drew by-hand back then; no other viable options!). CD3 Bitmap B also has a decent range of vegetation symbols should you want to add more variety, while the Hovels catalogue includes many rustic-looking plank constructions which might be useful as well. Plus the other options are large for this style, so there are numerous other building shapes you could fit in with some vegetation cover for unusual structures. If this Bitmap style doesn't appeal, there're also vector style options in the Elven tree-settlement line with CD3, and arguably even more options with the numerous additional vector catalogues.

Alternatively, you might look to the B&W dungeon styles - the OSR Dungeon style from CA97, for instance, has a useful range of vegetation symbols - though of course you'd have to draw your own buildings that way.

Good luck!