How do i get my map back after software upgrade on a Go 530?

Dug my trusty GO 530 out of the glovebox as our new car has a built in nav and i can give the GO 530 to my dad, i connected to TomTom home and it told me my device is old, yadda yadda, and then updated the software twice.

"Your device is old tat, but have a software update anyway", nice (i thought), reboots, tells me my device is old ta and offers me another software update, V. nice (i thought), now after a second reboot its starting up and telling there is no map installed!

How do i get my map back? Does anybody know the last version of the map they made available for the GO 530? It's still a cracking piece of kit that does everything my dad will need.

Thanks.