Temporarily downgrade MySQL to version 4 to retrieve old contents

I have an old mysql 4 database from a previous installation that I need to bring up temporarily to access and dump the tables. I have all of the /var/mysql stuff from the old backup, but if I temporarily move the Leopard directory of that name out of the way and try to bring it up in MySQL 5 under 10.5 server, it starts, but the upgrade steps seem too hard to complete to migrate the tables in the database up to MySQL5 standards.

I would like to just bring the old database up under MySQL 4 and move what I need out via a dump or other tools. How can I start MySQL 4 instead of 5 within Leopard? I see that there is actually a /usr/local/mysql-standard-4.0.25-apple-darwin7.9.0-powerpc in place already within Leopard Server; how can I make it start rather than the MySQL 5 that comes up when I start MySQL within Server Admin?