I had this very thing happen to me on ebay.I sold a dual quad vintage 60s manifold for $450.00 . The buyer send me a email two weeks later stating that the manifold had and extra threaded hole drilled in it that he would have to weld up .Wanted $50.00 refunded to him.He did not open a case.I just gave him the $50.00 off and chalked it up to the decline in the type of individuals that were coming to ebay and trying to get over on people.I had sold many things on ebay prior but only had one disatisfied cutomer(which I satisfied)aftewardS in all the transactions. Since then I have not sold on ebay.Rules protect the customer without regards to the seller.Not my way of doing business.Not worth it.Use craigs list or sell to your local antique mall.