The 1871 census contains an agricultural census. This can also be used in the town of Seaforth as it will show the Lot number of the resident and whether that lot was owned or rented (tenant) With this info you can then go to the land record office in Goderich and look up all owners of that property. In addition at the end of the name portion of the census there can be found a list of businesses and their owners or operators. This list usually include hotels, blacksmiths, sawmills, etc.
Not all microfilmed reels of the 1871 census contain this agriculture addendum of the name census, but the reels at the Huron County Libraries as well as the Archives of Ontario and the main libraries of most cities have this. Some of the microfilms at the Family History Centers do not have this info.