> Would I be correct in assuming that the firebird-ds.xml requires: firebirdSql.rar or equivalent whilst the oracle -ds formated file requires: jboss-ha-local-jdbc.rar and the jaybird jar files in the jboss lib directory.

Yes, that's how it is. However, if you have firebirdsql.rar (or
jaybird-2.1.1.rar) deployed, it should also work if you refer to it via
java.sql.DriverManager.

Roman