A name change does not invalidate debts incurred under a previous, or fictious, name.
You might want to consult an attorney who handles debt collections. You also might consider referring your claim for damage to a debt collection agency. It may be that you would be able to sell the claim outright, and see a little cash now, or it may be that a debt collector would take it on a contingent fee basis, which could result in more money to you later if the debt collection action is successful. Or you may pursue the collection yourself.
Public Record. Look it up at the Courthouse or your local Sheriffs Dept. 3K warrants a small claims, plus lost time.
It’s super easy and only costs a few dollars plus filing fees. Chances are he will ignore it and you will get your judgement. If he wants to reply, he has to send your filing fee back within 14 days of service.
30 days after your judgement is granted, you can garnish his wages. Hopefully, you have enough info that you don’t have to hire a PI, but if you do, you can add that to the 3K bill.