Field assaying scales

Set of assaying equipment, portable balance in wooden storage box, metal / wood, made by W & T Avery Ltd, London, England, c.1860. The case for the scales is made from unfinished timber and has a hinged lid, as well a small metal clasp at the front. When opened a small metal bracket can be seen in the bottom section, which acts as a base for the measuring equipment when fully assembled. Affixed to the inside of the lid is a sheet of paper with a hand-written index of the weights.
The balance is made from steel and features two pans suspended by a thin chain to the cross beam. Each of the pans are engraved in the centre, 'W&T AVERY / PATENT / LATET BEACH'. The beam is slightly rusted, with a swinging arrow pointer in the centre and a threaded end for the stem attachment. It appears as though parts of the suspension mechanism is missing.
Also found in the case are two steel poles, one solid, with a thread at the top and the other is hollow, and can be attached to the cases interior bracket. These poles act as the stem to the balance and are accompanied by a third flat rod with a compass point in the middle. There are also four brass measuring bowls, for use on the measuring pans. The largest is marked '2 / OZ / TROY' on the rim, two are marked '1/2' and '1/4' on the inside, while the fourth, more thimble like container, is engraved, 'D / MWS / DB / 69' around the outside.