"Weird glass ball, suspended by screws, in a metal frame, bronze or gold colour in appearance."
A: "It is a Campbell-Stokes sunshine recorder. You place a strip of card into one set of grooves in the piece that curves behind the sphere, point the opposite side of the sphere towards the equator, and the sphere will focus the sunlight to burn a track on the card. The card has hours marked, and more the card is burnt, the brighter the sunlight was."
Meese Inc. was a supplier of canvas bacpacks to US military.
Maybe a US Air Force mail satchel?