Consolidating builds for several projects can be a process which sometimes needs some creativity combining the tools already available.
Most of the time it is too risky and expensive to write everything from scratch - even if it is very tempting to do so. In case of Maven and Ant, there is the well known antrun-plugin which makes it possible to integrate Ant based builds into the Maven ecosystem.
Below is an example how to call Ant from Maven using a property file to store values which may change often.
Maybe somebody finds it useful.