After an attempt to get the site running on the main Tomcat through a cunning alias, which failed due to permissions complications, we've gone for a deployment in the Tomcat-dev. Cleared out two old projects ("dms" and "dhcn", obsolete ETCL sandboxes), I uploaded the Mariage cocoon, and had sysadmin chown the entire folder to apachsrv (so that eXist can modify its db), then chown the site directory back to me, so I can do development. The net result for Tomcat-dev is probably beneficial, because it's lost two projects and gained one. I've asked for the virtual host to be reconfigured.