I have a Mercury 150 XR2 (still has original decals on cowl) with serial number 5678292 on the plate located on the transom bracket. That serial number crosses to be either a 1980 or 1981 model V-150, it appears that the XR2's weren't produced till 1986. The previous owner said it was a 1987 model. Does anyone know how I can tell for sure the year and whether it is actually an XR2 model or not? Thanks for your help.