Hi. I need help fom those that know. I answered a private add for an old inline 6 cyl Mariner 115 the owner said that it was an 80s model. When I looked at it the serial number on the clamps was 3028516 I looked that up and it was a 71 model. The owner said it was fully rebuilt a year ago, the cowl says Mariner and has a red stripe, the tilt has 2 rams, it has a distributer and single big coil but the powerhead is black? I found some numbers on the powerhead 852-4843 with the letter A underneath the numbers. Whats going on? is the powerhead the low dome type and therefore an 80s model? What parts are interchangable between these years? Any help would be a big help thanks, Norri