Hi Jack, the trim pump was installed when my uncle purchased his 2nd motor for the boat so I believe it would be considered "After market" It does appear to be a mercury product though. I could not find a serial number on it. To answer your quesiton it is not a part of the engine it is mounted outside the boat and to the lower left side of the boat.
thanks for taking my question.
OH by the way I figured out how to manually tilt the engine up. It was a silver large hand screwable screw that you turn and after turning it I was able to tilt the engine up.
Hi Jack, I will look for the model number but in the mean time I found these pictures that look identical to the unit I have with the exception of the resouvour the knob to turn on it on my old unit is silver and large.
Actually, I meant to convey that it is indeed inside the boat on the back wall beside the outboard engine.