(In reply to Jack Streat) Well Jack, the most modern design of the Steyr AUG incorporated a unique ambidextrous feature, which allowed the user to choose which side the empty brass ejected. Now, the charging handle, on the other hand, probably wasn't able to do that, although, I believe the A2 model did. I wouldn't be surprised if it was. It's not uncommon to see a design like that. It, truly was a rifle ahead of its time (1977).
Have you ever thought of doing an AUG A3. I've done one myself, though not to the amount of detail you have, yours (especially the HK416) are properly AMAZING. Heres mine
Thinking of rebuilding in the same fashion, lengthways not vertical. Although it will be hard to make the decision, this being 3 years worth of mucking around, not really applying myself.