Rack goes on with 2 screws. One were your solo seat attaches and one were a 2up seat would attach. If want it no tool removeable you can get the thumb screws. Comes off very quickly.

The bag in the picture is only attached to the rack it didnt touch anything else.

 

In the picture of your bike with a "Bag straped to my motherswell for a 3 day ride", it looks like you have a bag at the bottom front of your frame. What am I seeing?

 

Harley has a setup that the seat goes onto the luggage rack. Has a removable pillion and back rest.

Check here
Here
and
here

May not fit depending on which dyna you ride.

 

I have a fork bag mounted down there. I made a metal braket to hard mount it so it doesnt rub the frame.

 

Draw something up and take into a welder, don't pay those high prices man, DIY!