I don't own an Iphone. But I would assume from blind observation that if you reinsert the original SIM card it would function in accordance with that sim card. Assuming that the information and functionality you seek is saved onto that sim card.
The only reason it wouldn't is if Apple saw through your illegal intentions and put some sort of fail safe into the phone. But I'm not an Apple product user. So I'm not familiar with what they do.
My advice would be to find the forums of whatever software you used to jailbreak or unlock your iphone. And ask there. Since they will know more about the method in which you released your phone. Far more than any typical user here may know.