Maven Assembly Create Custom Format - maven

Question

As part of a bigger project, I want to package some items I download together with some jar files as a .tar.gz package. And I did that successfully.
But now I want to "rename" that .tar.gz to something custom (e.a. to mypackage.banana)
Is there an easy way to achieve this?
What I have so far id accomplished using https://github.com/maven-download-plugin/maven-download-plugin
<build>
<plugins>
<plugin>
<groupId>com.googlecode.maven-download-plugin</groupId>
<artifactId>download-maven-plugin</artifactId>
<version>1.2.1</version>
<executions>
<execution>
<phase>generate-resources</phase>
<goals>
<goal>wget</goal>
</goals>
<configuration>
<url>${some.jar.file.url}</url>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
<url>${some.models.zip.url}</url>
<unpack>true</unpack>
<outputDirectory>${project.build.directory}/data</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2-beta-5</version> <!-- Old -->
<executions>
<execution> <!-- Build tar.gz archive. -->
<id>tar</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<descriptors>
<descriptor>src/tar.xml</descriptor>
</descriptors>
<finalName>project-${project.version}-el6</finalName>
<appendAssemblyId>false</appendAssemblyId>
</configuration>
</execution> <!-- /NewStuff -->
</executions>
</plugin>
</plugins>
</build>
using tar.xml:
<assembly>
<id>tar</id>
<formats>
<format>tar.gz</format>
</formats>
<fileSets>
<fileSet>
<directory>target/data</directory>
<outputDirectory>/data</outputDirectory>
</fileSet>
<fileSet>
<directory>target/lib</directory>
<outputDirectory>/lib</outputDirectory>
</fileSet>
<fileSet>
<directory>meta</directory>
<outputDirectory>/meta</outputDirectory>
</fileSet>
</fileSets>