If I list something with flaws I usually over state the flaws or list as Not working, parts only.

I can't sell it as new or good condition so it just lies around.

May as well get $10 or $20 for it and sell it as not working.

Buyer is always very happy when they find it's better than they thought.

If there is no way of getting a good price elsewhere anyway, sell items with flaws dirt cheap, making it clear for parts only.

If the flaws are only a few scuffs or marks then sell as seconds/rejects. And cheap to get rid of them.

Describe in the title, ebay's description section and the listing description. 

That should eliminate any ambiguities. You may still get the odd numpty, but what's life if you don't go out on a limb occasionally.