1837-38 Perth Directory
Nicol, John, grocer, 133 South street—house, 129
Nicol, John, grocer, 178 South street—house, 176
1845-46 Perth Directory
Nicol, James, grocer, 133 South street
Nicol, John, grocer, 178 South street
1848-49 Perth Directory
Nicol, John, grocer, 178 South Street—house, 176
1850-51 Perth Directory
Nicol, John, grocer, 73 North Methven Street
Nicol, Mrs John, grocer, 178 South Street—house, 176
I’m guessing that John has died and Mrs Nicol is continuing the business.
The other John perhaps a relative?