copy a tomcat6/solr configuration and content from one server to another

We are in the process of moving a badly maintained typo3 installation to another server. The typo3 search is implemented via tomcat and solr. We need to move the solr db from the old server to the new one, preferably maintain the ports and db name so that the existing typo3 search can access it. Moving the content of the solr db is optional, we can recreate the search index on the new installation if typo3 can access the solr db. Here is the catch, and please include this in your calculation: the existing (old) tomcat installation is installed from source (in /opt) on a debian8 server. the new tomcat installation is installed via package manager in the usual places at an ubuntu 14.04 system (ie config in /etc/tomcat6, data in /var/lib/tomcat6). you must make the necessary changes in the config and place the necessary files at the right places on the new server. you get root access to the new (test-) server and we copy the necessary files from the old server on your request (no direct access to the old server, sorry). your job is done, when the typo3 search on the new server is bringing results/is able to run a reindex. a short description what you did (bullet points) to make it work is appreciated.