when is a debt owed to me considered "paid in Full" and when do I send a "paid in full" letter?

my brother in law has owed me $1700 since April 2013. After having to threaten him w/small claims court he just now (feb 2014) put $1500 in my account. He says he is withholding $200 until he receives a notarized "paid in full" letter from me. I told him I was not sending it until the account was paid in full and he is standing strong on not sending it. I will be pursuing legal actions and will have to fly to long island where he resides from florida where I reside. My question is do I have a case and can I also ask for reimbursement of my flight, hotel accommodations, car rental and court fees all because he wants it done his way and not according to the law. He still has an outstanding debt and with his history of paying me back it would be stupid of me to send him the letter which I wouldn't anyway. I did advise him to consult his lawyer first but he insist he is right and it would cost me more to take him to court.