I have a 1980 20 hp tiller driven motor serial number 5610639. I cant find this serial anywhere online or on mercury's website i am looking for the parts to convert this to remote throttle and remote shift.The only thing i can find that comes close to this serial number is this All Models > Model 200, 20 HP > 4709593 & Up (USA) but i am not 100% i am looking in the right place before i order parts can someone confirm these are what i need?