Unfortunately there is no easy way to figure out what you used to unlock your 1.02.
Chances are if you performed the unlock before 1.1.1 was released or bought it on eBay, you have used one of the "bad" unlocking programs (anysim 1.0-1.02 or iUnlock).
It would just be safe to just virginize your 1.02 before running the 1.1.1 update.
After you update to 1.1.1, if your IMEI is the same number as the IMEI located at the back of your phone, your phone is not bricked and you can continue to jailbreak and unlock it.