Tomato firmware configuration

I have the Tomato firmware loaded into my Linksys router (WRT54GL 1.1). I acquired a second router of the same type and thought it'd be nice to duplicate the configuration. (if it breaks down or for whatever reason)
When I tried restoring the configuration, I got the error: "You cannot restore settings to a different router".
So I first needed to check what I had to change in the cfg file...

Source device:

gunzip -c tomato_v128_mDA3159.cfg | tr "\0" "\n" | grep "addr=00:1"
et0macaddr=00:16:B6:DA:31:59
lan_hwaddr=00:16:B6:DA:31:59
wan_hwaddr=00:16:B6:DA:31:5A
wl0_hwaddr=00:16:B6:DA:31:5B

Target device (to be overwritten):

gunzip -c tomato_v128_m4AF795.cfg | tr "\0" "\n" | grep "addr=00:1"
et0macaddr=00:1D:7E:4A:F7:95
lan_hwaddr=00:1D:7E:4A:F7:95
wan_hwaddr=00:1D:7E:4A:F7:96
wl0_hwaddr=00:1D:7E:4A:F7:97

Ah! It might check the MAC address! Let's try changing that...

gunzip -c tomato_v128_mDA3159.cfg | perl -pi -e \
's/addr=00:16:B6:DA:31:59/addr=00:1D:7E:4A:F7:95/g;'\
's/addr=00:16:B6:DA:31:5A/addr=00:1D:7E:4A:F7:96/g;'\
's/addr=00:16:B6:DA:31:5B/addr=00:1D:7E:4A:F7:97/g;'\
| gzip -9 > tomato_v128_copy.cfg

(NB: OS X didn't have a sed command that worked nicely with binary files.)

It restored the modified configuration file!
After resetting the modem and other connections that have the old MAC address in memory, I could connect to the internet again.