i'm confused, you recently purchased the truck, but then you drove it without issue for four months, your key lost sync, and you haven't been able to drive it for a year? that timeline accounts for 16 months.
why does it have a new battery? was that before or after the lockout? if it's really sat for a year, you'll likely have a lot of PM to do before hopping in and motoring.
can you let yourself into the car manually with the key and cycle the ignition on?
2003 Disco 2 SE7 - going to be buried in it
2006 RR Sport HSE - project
1997 Disco SE - SOLD
2003 Disco 2 SE7 - SOLD
1995 Disco SE - SOLD
2001 Disco 2 SE - SOLD