Wow, looks pretty sweet.

The front part of the saucer still looks a little stretched (tiles are bigger in the front portion than anywhere else), but it's looking really good.
Btw, just fyi, when I did the aztec for the registry area, I didn't do any fancy mapping.. I took a rectangular texture, and rotated it to fit the individual panels. Probably not quite accurate, but the area is small enough that it works.
The big thing to keep in mind when doing the aztec paneling is that is has to make sense structurally...well, relatively anyway.. the sovereign's pattern is the most scatterbrained thing ever, with very little organization to it. But the panels should always follow the larger construction lines of the ship. On a circular saucer that's easy, but the weird pseudo-ellipse of the sov is a pain. In general, try to make the smaller panels line up with big panels. I would try to describe it, but I think a picture is better.
Basically, the key to making the aztec panels look good is giving the saucer a grid structure, and sticking to it. With a circular saucer, this is extremely easy, you just get pie slices and concentric circles. The Sov's weird oval dish screws that up, and you wind up with something more complicated, with two separate focal points ahead and behind the bridge at the center. Really, a good example is the Galaxy dish, since it's got a nearly identical oval profile, just turned 90 degrees. I can't remember if I did this or not, but you might be able to overlay the Galaxy dish pattern on the Sov for a basic grid structure.
This is a portion of the upper saucer, with some of the grid lines highlighted to show how I tried to line up the aztec panels. It's not perfect, since the methods I used stretched the texture a little, but overall, the majority of panel lines on the saucer will line up with some grid. It's finding the correct grid that can be a pain.
Depending on your painting software, it might be possible to take a rectangular tile of aztec panels, and warp it to fit into sections of the grid.