I have had a look at the 1881 census but I can't see any mention of Salmon Inn, Horndean. There are 2 Inns mentioned at Ladykirk. One refers to the 'Casual Inn House' - UNINHABITED. Next to it is 'Inn', Ladykirk and the Innkeeper was James Moffatt 30 born England; Elizabeth Moffat, Innkeeper's wife, 29 born England; Adam H. Moffatt, Son, 7, born England; Elizabeth Moffatt, Daur, 2, born England.
So far I have only found 1 house with Horndean in the address: -
[New Horndean] Farm House, Ladykirk, Berwick, Scotland
John Webster, Head, Farmer, 74, born St Cyrus, Kincardine;
Wife, Agnes, 69, born St Cyrus;
Daur, Emma Duncan Webster, unm, 31, born St Cyrus;
Daur, Alice, 23, born St Cyrus;
Servant, Alicia, unm, born England;
Servant, Janet Shearlaw, unm, 17, born Ayton, Berwick;
Mother in law, Mary Carnegie, Widow, 95, born Logie Pert, Forfar, Fife;
Maybe I am missing something somewhere but I just can't see any other in Horndean so don't know if this is any help at all.