Actually I did that a few years ago (maybe 10?).
What happened was a guy saw something for sale, and then came back a week later looking for it again. But it had sold and I deleted it. So this guy tore his hair out trying to find it. He just KNEW that it was somewhere on THIS FORUM that he'd seen it.
He finally emailed me. Then I had to wrack MY brain until I remembered that I had deleted it since the owner notified me that it was sold. Once deleted I had no way to find it again.
So --- all together, maybe a half-an-hour lost by me.
That's when I decided to leave ads online and ask owners to just add SOLD to them.
In addition I have tried to go in every 6 months and remove ALL ads older than that. I certainly understand your frustration and I wish that I could find a different way to mark this as INACTIVE.
I will run the 6 month aging code and remove the older ones --- those that have sold and those that did NOT sell. Maybe that will help a little bit.
Also if you want the MOST CURRENT listings, I built and advertised this page a long time ago. I know that some guys are still using it.
http://vcca.org/forsaleparts.php