Oversized metal spanner, open ended, painted black. Possibly used on railways.
An article in the Coffs Harbour Advocate, 14 February 1973, states the spanner was
... dug up by drainers at Sawtell. It is believed to have been used on heavy engineering, such as bridge work.
Article "Spanner was too ... big for this job", Coffs Harbour Advocate, 14 February 1973.
