Can't Install / Uninstall MySQL

we have a server on which someone blew away the MySQL 4 progs directory
before installing MySQL 5. When installing MySQL 5 the installation
failed with an error stating that it was unable to create system tables
as the MySQL 4 directory did not exist.

We are now unable to uninstall MySQL 5:

[root@server1 local]# rpm -i
MySQL-server-standard-5.0.18-0.rhel3.i386.rpm
warning: MySQL-server-standard-5.0.18-0.rhel3.i386.rpm: V3 DSA
signature: NOKEY, key ID 5072e1f5
package MySQL-server-standard-5.0.18-0.rhel3 is already
installed

[root@server1 local]# rpm -e
MySQL-server-standard-5.0.18-0.rhel3.i386.rpm
error: package MySQL-server-standard-5.0.18-0.rhel3.i386.rpm is not
installed