Start calling local Mercury dealers and expand out. You'll have to buy a new unit from a Mercury dealer to maintain a warranty as Mercury does not offer a transferable warranty for lower units.
From time to time, Mercury does offer remanufactured Torquemaster lower units, but no telling how long you'll wait till one is available. They usually sell fast. Be careful of internet ads offering Mercury rebuilt lower units.
I got a public intoxication once when an officer saw me exit a convenience store and stumble on my way to the vehicle. I was already in the vehicle when he walked up but had never removed the keys from my pocket. He said he couldn't give me a DWI because he never saw me operate the vehicle and the keys weren't in the ignition. He could, however, prevent me from driving out of the parking lot if he had reason to suspect I was intoxicated. He asked me if someone could come get me. I believe everything that happened worked out the way it did because I was as respectful and cooperative as a person could possibly be. I never forgot how fortunate I was that day and have never drank and then drove since. Never.