The uniform display case was created for the purpose of displaying an outfit.
Usually you only want to show one part, be it pants or shirts, jackets, etc. Even caps or hats which are part of the uniform.
It is usually to treasure times you want to keep these uniforms. Mostly war lieutenants or soldiers are the ones who buy them and have them at home for display.
The measurements can always be specified by you, as well as the type of material with which you want it to be manufactured.