I would try to pick it up. Mac TV's themselves aren't exactly common either.

A black ADB Mouse could be fabricated in the mean time. Just paint a good condition, but yellowed mouse. You can take off the plastic shell and remove the components and get a really good even coat. The wire would need painting as well although it's a little harder.

Actually, yellowed mice are good candidates for retr0bright too - the case comes off easily, there's no silkscreened words or colored Apple logo or anything to worry about.