There are several ships on the Great Lakes that are 70 years old (cold fresh water isn't as bad for steel as seawater) and there a few that are even older.
However, 150 year-old ships are likely to be uncommon. It seems plausible that there would be some sort of manufacturing industry. In my opinion, Superior in Wisconsin would be a good location for this. Possibly Fraser Shipyards
http://www.frasershipyards.com/