Nice piece you got there for your birthday. I have a few of the items from the show myself.
Hmm I want to say that it from the 1st season. Only cause he didn't have any of his cool weapons over in the South America area. The 3rd season he was mainly rolling silent killer and then prison. His sword & dagger were present a lot at the start of the 3rd season. So either season 1 somewhere or possible 3rd season when he was trying to escape on the roof after killing the head guard guy. I'll try to scan across a few episodes and help you look.
Oh if your wife can look up the auction page for it in her ebay history. It should likely state what episode or atleast season it's from.