Please explain how this is any different than calling out any other trem rout — recessed OFR, Wilkinson, 2-point, etc. They have completely painted bodies with a generic rear cavity and "Your Choice Tremolo" in the in-stock section, so obviously that process is done at the end.
The NC code gives three dimensions for a tool path. Simply shift the dimension that calls out the rear wall (X or Y, depending on the orientation of the machine) forward by one inch. Z dimension (depth) should remain the same as an OFR rout. I used to do this for a living, so I know how easy it is.
Modding from a Recessed Non-Fine Tuner rout to an OFR rout might have to be a one-off, done by hand, but otherwise, NO, I'm not thinking in terms of one-offs.