I'd try a dump f the Verizon stock ROM for the base. I figure that it will be the closest as far as configuration.
Here's a link:
ftp://ppcgeeks.com/Raphael/Stock%20R...51064_Ship.exe
I also noticed that ImCoKeMaN offers some assistance on dumping ROMs in the stock ROM thread, so try asking him for some tips.
His thread is here:
http://forum.ppcgeeks.com/showthread.php?t=42741