Un-jailbreaking iphone 3g.what would happen?

So, my uncle(lives in USA) gave me his used iphone 3g. It was on AT&T & the contract was over(but he didn't unlock it) my dad gave it to one of his frnd or smone who unlocked it. To be specific jailbroke it. But now there's no itunes & safari on it. So I was thinking to restore it. But if I restore it will it be locked again?(I'm from Bangladesh so there's no chance that i can go to AT&T or smthing)

Why do you want you want to unjailbreak it? Just download safari and itunes (btw, I don't know why do you need iTunes, but there's no use for it in Bangladesh, I mean, you are not going to buy a single song for a dollar, are you?). You can use opera for iphone. Although I haven't jailbroken my iPod, I would have definitely done that if I were living in BD.