Yup BOI is a great idea. This will hit him where it hurts, and also give him a chance to explain his side of the story.

Other then that, take him to small claims court. That won't cost you and arm and a leg, and I bet he won't expect that, either.
He probably just blows hot air when he tells you he spoke to lawyers, etc.

Because IF he did, his lawyer would have not advised him that you have no case.

You have witnesses, but most importantly, he AGREED to replace the snake, several times. Hopefully you kept some of that
correspondence, but if not, even a verbal agreement holds up, especially since he kept stringing you along.

Since he is only an hour from you, small claims will be easy to do. Call his bluff, get your ducks in a row and go for it.

Just in my opinion.