Well, once you’ve worked out which regiment the old fellah was in, maybe you’d like to find out a bit more about his military service. Sadly, more than half of the service records, some say nearly two-thirds, were destroyed in a German bombing raid in 1940. But maybe you’ll be lucky. The National Archives at Kew holds the material which was not destroyed. Every soldier who fought in the war was entitled to at least one medal and the Medal Records can be found at the National Archives website and ancestry.com If the old fellah was killed, then the website Commonwealth War Graves Commission website may yield some information such as date of death, army number and unit, including which battalion was involved. The Scottish National War Memorial Roll of Honour can also be useful. Many local newspapers carried obituaries of men killed during the war and they might be worth checking at your local library. Some details of Pre-war regulars might be found at findmypast.co.uk. The folks at the Royal Highland Fusiliers Museum put together a list of services numbers for various Scottish regiments which were used for soldiers enlisting between 1920 and 1942;
Black Watch 2744001 - 2809000
Seaforth Highlanders 2809001 - 2865000
Gordon Highlanders 2865001 - 2921000
Cameron Highlanders 2921001 - 2966000
Argyll & Sutherland Highlanders 2966001 - 3044000
Royal Scots 3044001- 3122000
Royal Scots Fusiliers 3122001- 3178000
King's Own Scottish Borderers 3178001- 3233000
Cameronians (Scottish Rifles) 3233001- 3299000
Highland Light Infantry 3299001- 3377000
Records for military personnel from 1920 onwards, including the Second World War, are trickier due to privacy issues. These records are held by the Army Personnel Centre in Glasgow. They are only released to relatives - this requires the permission of the official next of kin. There is no charge to widows and widowers of the dead soldier for the information but all others have to pay £30.