No. As you can see below, on the Zero v 1.3 the camera connector extends completely to one end and the SD card holder to within a mm of the other -- and slightly outside that line there's a resistor (?) mounted (immediately below the holder in the picture), so you probably do not want to file anything off.
Looking at one in my hand I'd say if you removed the clip from the camera port first, you might be able to take a millimeter off that side and 0.5 mm off the other. Unfortunately this is less than 1/16" total.
The 2.6" measurement is also accurate.