Harry, very sorry to read your news. Hope 2017 is better for you.
As for the agressive dealer tell him to eff off, a deal is only a deal when the cash is received and the seller happy to part with the goods.
You are under no legal obligation to part with your car, do not get pressured by an aggressive dealer who just sees an opportunity to make a few grand for doing next to nothing.
If he has paid the money tell bhm to return it and thank him for his interest.
If he persists let us know his name and address and we'll send the boys round to persuade him to see sense.