The Dagor may be old, but people still use them. A mismatch between lens and shutter aperture scale suggests the shutter has been swapped. If the correct spacing between the front and rear cells, and between the cells and the iris have been retained, your example should be a useable lens. If these spacings are incorrect, performance will be degraded. Desting the performance of the lens will probably be the most practical way of testing this. The apparent aperture diameter as viewed from the front of the lens divided into the 9.5 focal length of the lens will give the correct f/number. When measuring the apparent aperture diameter, the eye should be some distance from the lens to reduce the effect of parallax.