To give a sense of the variety of texturing and the level of detail, here's the map_T for the western half of the map. Most of my effort thus far has gone into the Moresby and Dobodura areas, and I'm now expanding out from there. The interior is nearly fully forest covered--thank the gods!
I've overlaid and fitted Google Earth imagery, then traced out the various features. Principally: bare ground, dark swamp, light swamp, grass, light tree cover (I start with a base forest cover everywhere). Then for the larger, contiguous areas I mix in other related textures in a kind of 'noise' pattern to mask the worst of the tiling artifacts, as well as to make things more 'organic' in appearance.