Ebay problems ....

Bought an "unlocked" iPhone off ebay USA, which basically turns on and functions in terms of apps, but doesn't recognize the sim card or allow it to dial out. I have a feeling the mupet I bought it from didnt know what he was doing as he has received allot of negative feedback from the people that have the same problem as me.

Anyway, I want to do a clean format and restore the phone to its original state, and then use the http://ijailbreak.com/ app ... however I have no idea what the original firmware was since I didnt do it.

Under settings/general/about it states :::::

SERIAL NUMBER :: 7U745K33VP8
Model : MA712LL
VERSION : 1.1.1 (3A109a)

I am not sure if the "VERSION" means firmware current or originally, but i have a feeling it means current ... but want to double check this.

What is the best way to get the phone back to its original state so that I can try and install this : http://ijailbreak.com/

Cheers

M.