I tested your script : recover.sh
Under Gentoo distrubition the standard tftp doesn't work . I need use the linksys-tftp package.
emerge linksys-tftp to install the package and replace 'tftp' by 'linksys-tftp' into the recover.sh script.
Remarks : the default WL-HDD can be 192.168.1.1 or 192.168.1.220.
Thanks