Vintage Boxed W & T Avery Scales or Measure Breconshire County Council

It's not often I'm lost for words but this fine item has us well and truly stumped! We bought it - we love it - but we haven't a clue what it did other than it appears to be an official weighing or measuring apparatus?

The bespoke wood case bears an  engraved metal plaque that reads 'Breconshire County Council' and the device itself is marked 'W T Avery Ltd Birmingham' and bears the makers crest.

The main wood turntable rotates by means of a chromed rank handle which itself registers the degree of rotation on a scribed gauge. It has a 360 degree spirit level (bubble) set into the wood part and there are two steel risers with sliding clamps - but to clamp what?

A beautifully made piece - engineered to high standard and presented in a fitted box.