FWIW - Windows 7 x64 Ultimate
I sucessfully(ish) installed most of this mapset into MapSource using GMapTool 0.5.5 and unlocked with Garmin Unlocker.
Ignore all errors in both programs.
In MapSource I see the usual vector map to street level without topo detail and at least now have the option to select a smaller area to send to my Garmin Dakota where I can view the vector and raster maps.
Once installed into Mapsource I can now view the entire country in 50K raster format in all its glory with BaseCamp.