Re: Black Max 150 Cover, with serial # 175 hp Engine?
Not unusual to see different covers put on motors over time. Sometimes the originals are lost, damaged, stolen etc. In some cases people put a lower hp cowling on to conceal its true horsepower etc. Other times, it may be a complete powerhead swap where the original was damaged beyond repair. Many reasons, and near impossible to predict.
Post the serial number from the transom bracket, and double check the serial number on the powerhead itself. Given the serial number, some member here have access to the Merc database and can check a lot of details for you, including where it was originally sold etc.