Militaria is the umbrella term for collectible military objects, from buttons to vehicles. Surplus refers to equipment sold off by governments as no longer needed, while a reproduction is a newly made copy of a historical item, legitimate when sold as such. Period-correct describes an object — or a detail on one — that matches what was actually used in the era being represented.
Several terms are specific to the victory theme. V-mail was the microfilmed letter service used to move mail between service members and home during the war. Sweetheart jewelry covers pins and lockets worn by relatives of those in uniform. A victory garden was a household or community plot encouraged by wartime governments to supplement rationed food, and the tools and posters tied to that program are collectible in their own right.