Probably the first thing to do would be to trade in the mechanic, Sounds like a ten minute hero kind of thing to say to a customer.
There are many direct copies of OMC by foreign manufacturers though. Trim systems are identical looking but it looks like they had the "negative" turned backwards when they made their version. Crankshafts will even fit in at least one V-block although that is as far as the similarity goes on that example.
Probably the best example was the year that Suzuki decided to display their upcoming V-6 outboard in a glass case down at the Miami Boat show. Was asked to go over and take a look at it and found the raised OMC logo embossed in the transom brackets and trim system on that engine. We immediately called Suzuki who removed the engine by the end of the day. Got a personal apology from the president of Suzuki on that one which I thought was a pretty darned good thing for him to do. Think I still have that letter somewhere in my files.
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