During the process of preparing to secure the forum, I realized the OS that the server runs is almost out of support. The process is going to be much more involved than I first expected.
It seems the best option is to move the forum over to a new updated server and secure it then. I don't know when I will be doing this, but it's going to cause some downtime.
The process I'm planning on, is to put the forum into read only mode, create a full backup, restore that backup onto the new server then do all of the updates and security there before taking the current server down. This will provide the shortest amount of downtime and insure the new server is running properly before taking the current one down.
I'll keep you all updated as I work through the details of the process.