Where can I find a picture of the copper wiring connection for a Nutone LB-12 chime?

Shows a discontinued model. However, from the wiring schematic, it looks like the hot goes to the middle terminal and then the front goes to the solenoid with a double ended bumper, the rear to the single bumper. That way the front goes ding-dong and the rear ding.

Here you go, courtesy of Nutone. The installations are appended below in the form of a "PDF" file.