Okay so this snake is not a cheap snake so I'd be rather surprised someone would just dump it (although not totally unheard of) assuming this is what really happened. Your neighbor just 'found' it yesterday.
Did you really do due diligence in trying to find it's owner before just deciding 'okay it's mine now'?
I understand you are excited, but if *you* lost this, wouldn't you hope someone would try their best to find you to return him?
Sorry for being so skeptical but seen a lot in this hobby.