I purchased a Kings playgym model PP503 off ebay and have noticed a coating of brown, looks like rust, but not, on parts of the pieces. I called the seller and he said it was a coating that was put on the inside of the framework and it should wash off. Well it is washing off, but I am still skeptical. I purchased a Kings cage 11 years ago and I didn't have these issues. Should I just wash it off and put it together or pack it back in the box and return it?