Green’s Dictionary of Slang

a suit of clothes.

1879		‘’Arry on Crutches’ in Punch 3 May 201/1: A crutch-handled stick is percisely the very hidentical thing / [...] to put the last touch to my brand new tog-up for the Spring.
1886		S. Watson Wops the Waif 4/2: Wops, who was ‘getting a new tog-out.’.