OK well that all looks very encouraging - my version is 1.2 so the "--examine" looks a bit different, but the important thing is it is correctly detecting the RAID partition type.
Was the array resyncing to a spare drive when the NAS died by any chance? It looks like it's ignoring the 'active' device and trying to assemble from the 'spare' and another (missing) device.
It worries me a bit that it seems to have assembled TWO arrays - my guess is it put the active device in md0 and tried to make another array in md1 out of the spare. Let's try
sudo mdadm --detail /dev/md0
and try to figure it out. We may have to pull both apart and re-assemble giving it the partitions explicitly instead of using --scan. Or maybe we can remove the spare from md1 and add it back to md0.
sudo mdadm --detail /dev/md1