I'm not sure what the mirror is worth, I'd also love to be able to tell you guys what the coating is and what F ratio it is, but I don't have that information
... I was told I can guestimate the f ratio by shining a light at it, bringing it into focus and dividing that focal length by the aperture, so I might try that. Would someone care to give me an approx value of this mirror, I know I paid alot for it when I bought it but that was years ago.