Remotely SSH to IP address in home network
One way to do what you want here is to add a port mapping in your Airport Extreme that points a non-standard remote port (e.g. 8022) to port 22 on your local 10.0.1.104 machine. Then, you can specify a different port in your SSH client (e.g. '-p 8022') to gain remote access.

You could also SSH into 10.0.1.100 first, and then SSH into 10.0.1.104 from that machine.