This kind of hack has been made for nuvi 37xx and following, but works in every CX compatible units as stated in linked thread.
In 1300 you could use map FID ,but you need original map and unlock with Jetmouse and NT map FID and PID 2.
These FID 800 maps are already unlocked in CN part so .unl for FID of CN map part is useless, you must just unlock MMR part with FID 800.
To test it you must simulate and put your position on map in the city ,in this case Amsterdam, then ask for a route from your position in Amsterdam to the address you choosen to reach in Amsterdam.
All this is explained with pictures in linked thread ,but nodody reads it
[Only registered and activated users can see links. ]
Edit :I send you by pm the .unl to put in folder