The blank "cmap card" that the data was backed up to can only be read by the RDP139 at this point. When these cards were prevalent, C-Map had an adapter that would allow it to be interfaced with a Windows computer (like an SD card reader today). To get that data to something that can convert the points to work on the NAVnet 3D system, one would need one of those converters or a NAVnet vx2 (saving data to a 2GB or smaller SD card). Then, once the data was on a Windows computer, a program would be needed to convert to NAVnet 3D format.
Bottom line: First thing that has to happen is the files need to get onto a Windows computer. Once on a Windows computer, they can be converted to work with the NAVnet 3D system.