The National Portrait Gallery in London has many portraits by William Salter of famous and not so famous British officers of the Napoleonic Wars. To access them:
1. Go to: https://www.npg.org.uk
2. If you do a search for William Salter you will not get many results. However his portraits can be browsed using NPG numbers between 3690 - 3769
3. For example if you type 3762 in the search box you will get the portrait of "Sir John Ormsby Vandeleur"