It does get tricky now, with possible wrong viewings

The issue will be the commoness of the surname of M(a)cDonald. MacDonald is one of my main lines, in similar area, so I know how very hard it can be to identify people on the indexes.
What can help sometimes is to narrow down events to give you a time window for possible deaths. Sometimes looking for wife's death first can help as you can look for wife's death using both maiden name and married surname which can make it easier to find often. The wife's DC will show whether husband is still alive or already deceased.
The other way is to look at children's marriage certs as again this will show whether either parent was alive or deceased. In your case with Donald b. 1874 v. late marriage in 1931, that won't help! Looking for possible siblings marriages to help with this might also be tricky due to the common surname.
This was the family that we had from earlier in 1881:
Donald McDonald 39, station master b. Alvie Inv.
Elizabeth McDonald 40 b. Inverness, Inv.
Alexander McDonald 12 b. Kingussie, Invernessshire
Isabella McDonald 10 b. Inverallan, Invernessshire
Ewen McDonald 8 b. Aberfeldy, Perthshire
Donald McDonald 6 b. Aberfeldy, Perthshire
Mary McDonald 2 b. Dyke Morayshire
Address: Brodie Station, Dyke Morayshire
Monica