Glock carry question

[Hoosier45]

Hypothetical question here.

Let's say you had a buddy that was back from Iraq. While in Irag he had been part of a team that seized a large cache of guns, and he managed to bring one back, under the radar. Lets say it was a Glock 19 Gen 3. Lets say he knows you're a collector and says "Here, buddy" and gives it to you. Lets say the serial numbers on the barrel and slide are different from the serial number on the frame.

Would you be worried to use this as a truck gun or sometimes carry gun? Without knowing the history of the gun? There's a chance this gun was never in the US. There's also a chance that the gun, or part of the gun, is stolen.

It's a nice gun. I just don't want to get stopped with it, have the serial number run, and have some trouble on my hands.