Have you taken it out for a look see? Tarnished or not you might be surprised. Some of the Coulters were pretty good.

If it were me I'd send it to OWL for recoating and testing. Based on both my visual test and what you get from OWL you can decide whether or not to refigure it.

And while I agree that you are better off rebuilding the scope I'd hang on to it and use it while you build a better mouse trap on the side.