New Zealand Shipping Company (NZSCo) uniform 24mm button by Oliver.

New Zealand Shipping Company (NZSCo) uniform button. The crossed house flags (US flag on the left, and the flag bearing “NZSCo” lettering on the right) flanking a central mast/spar design are a signature of NZSCo officer’s uniform buttons, (later absorbed into P&O in 1971), and this style of gilt roped-edge button was worn by officers and crew on company uniforms.  

This is maker’s/retailer’s mark on the reverse of a plain shank button , reading “A. OLIVER & SON • LONDON”