I have no idea what it should be doing to be honest. I'm brand new on this library stuff but I really want to learn this.
What that bit of code is says is that there is somewhere, outside of this file (extern), an object, of type SerialPreset, named SerialPreset.
So, where do you actually create that object? The problem is that you don't. Having an object with a name that is the same as the class is likely going to cause you problems. So, you need to change the object name in the header file, and you actually need to create the object in the source file. Look at how HardwareSerial.h and HardwareSerial.cpp create an instance called Serial.
I cant see "telegraph" in the original morse code.
I can't see the original morse code, so, we're even.