You can get the file @ http://dev.n0ll.com/TechNet/phidget/phidgetsbc-full_18.104.22.16811022-with-3G.bin
When you have reflashed your SBC, you need some extra config.
$chmod +x 3Gsetup.sh
it just a file with commands, you can pick out the one you need..
I'm collecting all my notes, and gonna try and update the guide.