It looks like a simple enough shape/contour that one can probably make (or have made) a custom panel quite easily. Depending on what it's like on the inside you may be able to mount the empeg (or other or additional DIN unit) without internal mods. Otherwise It may not be too difficult to make a bracket either.

The good thing, from looking at those pictures, is that the stereo seems to be isolated, at least from a UI perspective. This would be a PITA if the environmental or other controls were part of the same control layout.