Is this really military?

[AncientRuin]

These items are from a Donald McNaughton who was born in Fort William, Scotland in 1803, emigrated to Australia in 1837, and then on to New Zealand in 1840 where he remained until his death in 1860. Family legend has it that he was a "captain in the army", but the passenger lists I can see have him as stonemason.

So what does the carefully carved wheat sheaf mean?

Probably not relevant, but one of his brothers was in the Grenadier Guards.