Your hwid is 972., so yours is US unit.
Please recheck hwid within firmware you flashed (972 or not.?)
In case of rebooting loop., it's most probably from the wrong files in nuvi.
You need cure firmware.
Cure firmware that modified to ignore the wrong file(s).
It means you have to know what file(s) is(are) wrong.
If you don't know., so you have to create cure firmware to ignore the suspected file(s).