While looking for information on the Rough Hollow Bridge, Hermitage, Hickory County, MO, I found your information. I have an outline of the County 1830-1950 compiled by the Hickory County Historical Society, and it states that a wire suspension bridge was built in 1896 at a cost of $2100. This may be the swinging bridge.
The Rough Hollow Bridge framed with iron, East of Hermitage, over the Pomme de Terre River, was originally constructed in 1890-1891 at a cost of $5,699. The original bridge was torn down in 1931 and reconstructed at its present site in 1932 by Ross Hardy and C.C. Brookshire. It is still used today (2007), however, the wooden planks are wobbly and sometimes missing.