I’m looking to purchase an ‘08 trawler. It has twin Yanmar 6LPA-STP 315 hp engines. Oil samples from both motors, and starboard transmission came back normal. The oil for the port transmission came back abnormal with iron at 104 ppm. Owner states that when the oil is changed the port oil comes out darker than starboard. I’m thinking that if the oil is darker that it’s probably clutches starting to slip and will need a rebuild. How concerned should I be going forward with the purchase? The boat performed great during the seatrial, with no transmission symptoms.