I'd just like to say thanks again for the tip about reducing the mesh2 size.
I removed uv data for all parts that don't get image-maps and wrote a
program that reduces the precision of all vectors from 6 decimal digits to
4, at the same time removing all spaces (from the vectors). I ended up with
a reduction from 11.3 to 6.6 MB. Not too shabby considering the rendering
result looks exactly like before. :)