Adam D. Ouellette

Hey folks, just got a really beautiful example of a Pre-36 iscorama off eBay. However, while the optics are incredible, if i tilt the lens up and down it sounds like there's an element ever so gently tapping back and forth inside the middle of the barrel. It's very subtle. Should I keep this lens or return it? Or get it serviced by somebody? What are my options here?