My primary references are the original mesh, some aspects of... was it Galemp or Vasudan Admiral who did the HTL Apollo?... the current high-poly mesh, as well as the cutscene. The idea is to capture what we know from way-back of the Apollo while not diverging too far from it - I'm not going to pull a Boa here.
...I will note that I will NOT include a forward canopy pillar when I get around to that component, and I will make sure an appropriately-sized pilot/pilot and WSO (for the GTB Apollo

) get placed in the cockpit. I'm also going to axe those hideous "frog-ears" on the current HTL model. The cutscene model (my primary source for general shape) didn't have them, and I won't suffer to put those things on.
As for hull details, the current HTL mesh got most of them right in my opinion, and now it's just a matter of adding some finer details to them. Everything else should be fixed with a new texture map... I'm no texture artist, so hopefully someone will step forward to take care of that problem.
Now, I'm not opposed to using the concept art so long as it doesn't contradict too much detail from what we know of in-game. The Wiki certainly has a concept art page, but it's at a pretty low resolution. What VP should I crack into to find this stuff? Knowing that could help quite a bit.
Lastly, I'll post the current developmental from my notebook - I'm trying to maintain the main slab-sided surfaces of the Apollo's cockpit armor, and the primary reference apart from the cutscence model is the original Apollo mesh, which undoubtably was derived from the cutscene ship or vice-versa (the similarities as well as certain texture regions are just too obvious). However, upon noting the cutscene and looking at the mesh, there is a little more curvature than you'd think to the ship, hence the reason for the higher poly-count apparent in the... rather early stages of the model you've seen so far. Getting the "slabs" right while avoiding the "dents" (which were certainly not intended to be there as a design feature) is something that no one has seemed to get so far...
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