The cabinet card above, which shows the two Glasgow addresses, must date from within a year of 1897, since he came to this address in 1896 and left the earlier Bellgrove St. in 1898. Note the area of tissue attachment at the top.
The two cards below mention only Jamaica St. in Glasgow and an Edinburgh address. Dunbar operated in Paisley from 1903 till 1907 but this address is not included, so these cabinet cards should date to between 1898 and 1903. From the styles, the one on the left looks earlier; unfortunately, the numbering on the back suggests differently, so there is some doubt about the dates.
The next cabinet card below is on coloured matt card, with an art nouveau design at the bottom, and can be dated to the mid Edwardian years from the presence of the Paisley address.