SGH-I337 unlock for Verizon sim

[Rebel331]

Hey everyone! I recently dropped and completely ruined the screen on my Verizon SCH-I545. Not just the glass but the actual display to the point where nothing comes up at all, even though everything else works(ie making notification sounds and lighting up the keys), My dads friend gave us an ATT&T SGH-I337 that I just got unlocked. I completed the entire online request and received the code that they send by email while "reviewing the request". I inserted my Verizon sim from the SCH-I545 and entered the unlock code in the dialog box. It closed out and no longer says anything about the card being locked. I get cell signal but when I try to make a call it cancels and says emergency calls only. Now a Verizon affiliate store rep told my dad that the SGH-I337 would work just fine with Verizon and that the only required steps would be unlocking the phone and then buying a Verizon sim and inserting it. I live outside of Boone NC where I am not completely on Verizon's towers(I'm pretty sure). The local carrier is Carolina West and I am assuming when I activate any phone in Boone and bring it back to my town, I am using Carolina West's towers. So my question is will the SCH-I337 work in my area(how do I tell what towers I am using?), will the phone even fully work when I am in a Verizon city like Boone or Charlotte NC, and if none of those options will work could I take the motherboard from the SCH-I545 and put it in the SGH-I337's housing? The SCH-I545 was the white frost and the housing is pretty beat up and I would like to use the SGH-I337's housing since its black and in mint condition. Thanks in advance!