Okay I sent a link to my ship to Zedi and TDW. There is two issues with it that I know... I thought I solved it but something happened or I was wrong.
My ship is almost like the one in Sh 4 folder. All the images and materials should be using same system than in SH 4. It uses .dds files and no embedded pictures. Basically the only difference is the DMG_col-addition!
All the maps and textures show basically correctly and it looks pretty much the same like the one in SH 4 (NOTE: this uses Sh 4 stock occlusion map).
Otherwise the import works (well, no reflections) but for some reason the sun light was showing on the wrong side! It's a nice effect that I couldn't see in TDW's version, and I struggle to keep it.
Well I managed to correct the sunlight direction by editing the UnifiedRenderControler and changed MediumLODDistance to -4. Now the light works as it should and it doesn't change back even though the camera is near the ship.
This would be almost perfect but something bad happens when I changed the value: The holes don't show anymore below the water (they were visible before the LODdistance edit). The other thing is that I managed to add visible SH 4 guns to the ship that were rendered. Now they are black.
.
So what is causing the sunlight direction bug? I bet it's the UnifiedRenderContoler, Sh 5 ships don't have that. I think we should use this Dat-file structure, it's the same in SH 4, so the importing would be almost like drag and drop!