There is quite a lot of code in the Qpid C++ code base that is vestigial (like your appendix). In the name of easier code maintenance we should remove it.
I will detail some of the things I have found as comments to this JIRA, if they attract sufficient comment they can be broken out as subtasks to this issue.
Most of these issues are small and involve unused member functions or unused/potentially unused interfaces or interfaces implemented unnecessarily.
Much of this is still the fallout of removing the old cluster work which added hook (and hence interfaces) in lots of code, now that old cluster is gone the interfaces/members remain, but are unused anywhere.