Connect to OSX via AFP over WAN with a Time Capsule on network?
You could forward port 548 to your MBP server to get back the old behavior of allowing afp://**** to connect to your MBP server instead of your Time Capsule.  This would definitely make your Time Capsule AFP server inaccessible from the Internet and might (but I would hope not) make it inaccessible from your LAN.  Try it and see.  Here is one of many web pages describing how to set up port forwarding. 

You can pick any public port you want > 1024.  I'll pick 9898 for this example.  Following the instructions on the linked page, in step 4 set up port forwarding like this:


Description: AFP access to MBP
Public UDP Ports: 9898
Public TCP Ports 9898
Private IP Address: the LAN address of your server, e.g. 10.0.1.100
Private UDP Ports: 548
Private TCP Ports: 548


Then you can access your server from the internet using afp://hostname:9898