I just had to do this.... Really!
The shield is the same one from MontagueFlange - I posted it again to make it easy for you. The Cat-Back file is the same but with an area carved out for the doorbell button and plunger, and the Butt-Actuator is self explanatory...
The DoorBell is a cheap replacement button from Home Depot - just locate and drill a 5/8 dia hole in the shield for it.
The Shield and Cat-Back were printed at 140% size, and the actuator is already sized for this. Please enjoy this responsibly....