He needs to first confirm whether the iPhone has new bootrom or old one. There is no working jailbreak yet for iPhones with newer bootrom. Download f0recast or tooljail to find that out!
Sorry a bit OT here , Pat I also have an friend who has an unlocked iPhone 3G with modemfirmware 05.12.01 and fw version 3.1.3(7E18) .. I think its unlockable can you confirm that ?