The design of this badge derives from the centrepiece for the Home Service helmet plate of 1881 (ie after the numbered centrepieces had been replaced). The badge was modified in 1902, with a king's crown replacing the queen's, which helpfully dates this piece.

This badge would have been worn continuously from 1896 until the introduction of Stabrite badges in the early 1960s. However, looking at the reverse and the brazed construction of the copper lugs with the all-important feet, I suspect that this is a 1914-era badge.

This is the OR's glengarry badge of the 5th Battalion. It was worn, with a Queen's crown, from 1887-1901, when the imperial crown (as chosen by Edward VII) replaced Queen Victoria's crown.

This replaced the previous numbered example worn on the glengarry cap. A slightly larger version was worn on the racoon skin cap for dress and on the foreign service helmet.

The Duke of Atholl was the only man in Britain allowed to raise a private army, so this might well be for his unit. However, other members of his clan/family would have been entitled to wear this.