Stewart and all,
The narrow gauge railroad historian Linwood Moody was New England into his core.
In one of his books he says that his job was to muckle into, that is look into the locations of any and all narrow gauge equipment. And in his case it was two-foot gauge not three-foot.
I am a maritime historian and here is another use of the term caboose. On sailing ships before 1850, there was a small wood deck house just lashed down to the deck with ring-bolts.
This was the place where cook did his work. Some of them were washed overboard with their contents includong the Cook! In later years, the deck house was iron and became a larger
structual part of the deck.
Sailing ships are another kind of old things that move!
Ted Miles, Assistant Curator, San Francisco Maritime Historical Park, retired.