The first two reverse designs above are typical 1862 or 1863. They are on thin, square cornered card with no embellishment on the design.
The handwritten comments on the third below read 'To Janet Campbell, as a token of Remembrance of John McTaggart. Farewell, Janet'. There was an MP of this name served Wigtown and district who died in 1867, which would be a suitable date for this cdv, though of course the photo would have had to be taken before this. The curved ribbon says Hardie was established in 1855, which is just one year before the date found for Hardie & Naismith at this address..