Yowza!
And BrotherByron, you should reduce the number of sides of the circles that compose the engines to 16 or 12. Right now they take up too many polygons.
This needs to be done right away.
Speaking of which – any volunteers for UV'ing and texturing? 
The existing Poseidon UVs are 512x1024, if I remember correctly, which should be just fine. We may need to UV generic greebling with some texture that would fill in some gaps in the map, and it probably needs glow/shine/normals too.
Isn't the whole point of the original Cargo Container is that it was built so the Poseidon could simply slide down the arms into the grooves and carry it away? Why would the container be shaped that way if not for non-rotating arms?

There's a FS1 CB Ani that demonstrates exactly that.
Bobboau, we appreciate your enthusiasm for docking animation but it seems a bit misplaced here. The Vasudan Maat, Bast, and Isis are all designed for docking animation (from the concept art at least) and could be done more faithfully.