The following images are from Culloden: The Swords and the Sorrows the Nat'l Trust for Scotland, 1996.

Here are some earlier (1600's) types, with snaphaunce locks, mixing brass and steel, and with differing butt styles:



Notice that a 'brace' of Scottish pistols has the locks on opposite sides of the guns: left side for the left hand pistol, and vice versa:





Here's an early (1670) all-steel flintlock 'dag.' A lateral sear catches the back of the hammer on this one: