Dimensions are all over the map on these things... Sheesh.
I have a bunch of the Powerwerx outlets in USB, cigarette lighter and Anderson connector configurations, plus a Blue Sea USB of the same sort, plus a couple of Powerwerx mounting panels with the recessed holes. This should represent a decent sample of what is out there.
Looking at the outlets, the body diameters run from 1.12" to 1.13" for the Powerwerx pieces, and the Blue Sea is at 1.108".
The flange diameters run from 1.432" to 1.45" for the Powerwerx pieces and 1.382" for the Blue Sea.
The flange thicknesses run from 0.064" to 0.1015" for the Powerwerx pieces and 0.0730" for the Blue Sea.
Then, looking at the Powerwerx mounting panels, the holes (which are not exactly round) range from 1.140" to 1.169", the flange recesses range from 1.464" to 1.4935" in diameter and 0.1215" to 0.1360" in depth. Note that the depth measurement is intended to include the dust cover, and I don't see the dust covers as being viable in the tight space afforded by the XJ dash bezel.
I would be inclined to go with hole diameters of about 1.15" and flange recesses of 1.47" diameter and 0.11" deep. Know that the dash bezel is going to overlap the outer edges of the flanges, but I don't think that will make a functional difference.