I converted the Habro toy Dark Eye droid last year. It's still undersize, but it looks MUCH closer to the real one than the toy does. Here's the entry from my blog - hope it's of some help to you:
This started life as the Electronic Sith Droid Attack Game (which tracks you using IR and fires foam disks in your direction), as can be seen in the above picture (unaltered). Obviously, for playability sake and to accommodate the disk-firing action, some artistic liberties were taken.
So the main jobs were to reposition some of the wire connection points, sculpt in pieces that are missing (front and back 'flap' corners), add a domed lense to the front and top left camera, and fill every gap that shouldn't be there (this took AGES..... and I must admit - it's not the most invisible filling work in the world):
After this work was finally completed (much Milliput-ing, Dremeling and sanding), the whole thing was sprayed black, the lenses were painted high gloss black, detail pieces painted aluminium, and new, accurate wiring added:
Oh yes, and the original black plastic pole and base it sat on was replaced with a slimmer, shiny aluminium pole and base. At some point (if I can figure out how to make one) I will replace the antennae with one that is twice the length to make it more accurate.
Ready to hunt some Jedi!