These records are not held by the relevant regiment, but in various other places.
1760-1913
Soldiers Documents (WO97s). Held at the National Archives at Kew. These records are now on-line at Find My Past.
NB There are few records for the 42nd & 73rd prior to 1800. There are no records for those who served in the French-Indian or Revolutionary Wars in North America.
First World War
These records are held at the National Archives at Kew. These records are now on-line at Ancestry.
NB These records were bombed during the Second World War and only 40% have survived. Medal Rolls for this period are also useful and can be found on the Ancestry and National Archives websites.
Post War
These records are held by the Army Personnel Centre.
These are confidential documents and, as such, are available only to relatives.
General
The Black Watch, Eric & Andro Linklater.
The Black Watch: The Inside Story, John Parker.
The Highlands Furies: The Black Watch 1739-1899 by Victoria Schofield
First World War
A History of The Black Watch in the Great War, ed. A G Wauchope.
Second World War
The Black Watch and the Kings Enemies, Bernard Fergusson.
The Red Cross website may offer details for those captured during the First and Second World Wars.
The Roll of Honour for the First World War to 2006 is held at the Scottish National War Memorial in Edinburgh Castle.
For the First & Second World Wars, these can be found on the Commonwealth War Graves Commission website.
From the Second World to the present day is covered by the Armed Forces Memorial located at the National Memorial Arboretum, Alrewas, Staffordshire.