So a while back, I tried jailbreaking and unlocking iPhone 3gs. It was a replacement from Apple for an old 3gs that I was having issues with. I then decided to buy a new phone and wanted to give this one to my parents who are on another carrier.

I was able to jailbreak successfully. Then realized that because when Apple gave the replacement phone it was on ios 5.0.1 that it could not be unlocked. I tried a few suggestions that were roaming around at the time including flashing the ipad baseband (6.15.00). Still nothing, so I've been waiting for time to go by a unlock to be created. After looking relentlessly, I only have more questions. This phone according to the SN and a couple programs has the new bootrom. Which would indicate that when I flashed the iPad baseband, the phone should have been bricked or at least partially bricked in that wifi etc wouldn't work. The phone is functioning other than it will not recognize the TMobile SIM card, it still shows no service. I no longer have the correct size ATT sim card to use.

iPhone 3gs with ios 5.0.1, 6.15.00 baseband, new bootrom

So my question, since the iPad baseband is already on the phone can I run the unlock? If I do, and it doesn't work, what is the worst that can happen and can it be repaired?

Thanks for helping me sort this out. It is so weird, I haven't found anyone with a new bootrom that has the 6.15.00 baseband, I'm wondering if the programs and SN are incorrect, or if when I flashed the baseband, if it didn't do it correctly. Confused!