My Dad was at the dump and noticed that someone had thrown out a complete, except fot the tiller, Evinrude Fleetwin 7.5 Aquasonic. It is fairly clean, but is seized. That is not a big problem. I need to know what year it is. Serial # 7518-31385. I have another Aquasonic, belive it to be a 1954, 7.5.It is complete and not seized, but the lower unit has noticeable corrosion. Serial # 7514-10092. Can I use these both to make a complete running out board?