AU and personal design is a forum thing.. The archive for the real thing.
After reading some more... To get your AU or personal design in the archive, should be sort of bonus. I'll come back to it when I get home.
I agree on the need of policing the non-IRL designs, but I see two "simple" ways of setting the AU designs apart reliably in a common archive: 1) add AU-specific entries in a list-based country field, or 2) a separate "reality level" field where you can tag your drawing as real/never-built/AU during upload, which can then be used to filter the DB (say, with "AU" category filtered out by default).
Now if the aim is to reduce the amount of AU stuff on the site or the workload for the checkers, the submission itself might have to be reviewed...