Kanopus assumption is the right one. rgn=49 is region 49 of the memory of the unit. Name not important. No connection with the lower 49 states. Aviation data should be on different region. Yes, I am not sure is region 49 a correct one for that unit. May be it could brick the unit. May be, may be... Don't know is c510 a good example. If I am not mistaken it uses flash memory where can easily be entered in USB Mass Storage Mode.

P.P.:...you should make dump from that region (if possible) to be sure that this one is the correct one...gpsdaemon...0x31...DSKIMG...and again responsibility is yours...