just call it north.img and south.img
leave the jcv file with it's original filename.
g2s is traffic trends - you don't need it
Asr is in .system/ASR for voice command (you don't really need it for holiday)

Do a full backup of your nuvi before copying files to the main memory.
I usually just copy the img and the jcv files to the memory card. I remove the memory card before connecting to Garmin Express.
on memory card make folder POI and copy your GPI files inside.
Don't contaminate your Nuvi main Memory with downloaded files can crash and difficult to fix.