Pictures would be helpful. Absolutely useable. That Wollensak Beach 16" is a very desireable lens. The numbers are the aperture scale and I've yet to find the literature that describes the wierd system but you would find 11.7 = f4.5, 11 = f5.6, 10 = f8, 9 = f11, 8 = f16, 7 = f22, 6 = f32
Hard to make any $$ with it because they are from an era when the value of time spent is quite different from now.