The saucer segmentation is wrong. It's first split up into 3 segments per 90degs, then less more visually, each of those segments is split up to 8. It's like this dorsally and ventrally, but on the ventral side, you need to rotate the 3 seg grid by 15degs (cause 90/3=30, 30/2=15) and do the extra 8 from there, the running lights should wind up dead center of one of those small segments.
The circular ones look OK.
You say you are doing this on 2048's? Then use 1 pixel lines for the segmentation.
Second:
Don't use generic patterns on the base coloring. Make them plain. Oh, and the Ambie doesn't have aztecing whatsoever on the saucer, neck and sec hull whatsoever ya know, only those huge ones on the nacelles.