This website has early 1970s pictures of the Muscatine waterfront that includes photos of the original high bridge that was demolished after the current Norbert F. Beckey Bridge was built.
The original old bridge looks like it retained it's original wood deck until the end.
It also has a 1973 photo with the old high bridge being imploded with the then new bridge in the background.
Even more information including span lengths and details of construction can be found here: http://books.google.com/books?id=3mDOAAAAMAAJ&dq=Muscatine%20Bridge&pg=PA470#v=onepage&q=Muscatine%20Bridge&f=false
Information about this bridge can be found here: http://books.google.com/books?id=cHkUAAAAYAAJ&dq=Muscatine%20Bridge&pg=PA305#v=onepage&q=Muscatine%20Bridge&f=false