From a google image search appears to be from a late 50's Jag XK120. Decent condition for being 60+ years old.
It does have a few scratches on the surrounding bezel. I did spin the back of it with my drill and the tach needle moves. It seems accurate for the speed of my drill but no guarantee on that. It is worth noting it does turn with more resistance than other cable tachs I have spun. Please look at the pictures closely and consider them part of the description. Ask any questions you have.