Here are some pictures of my take on the mailbox mod. I have not been able to try it out yet - that is coming this weekend. I tried to make it so I could use the mailbox or the regular chip loader depending on what I am doing - although I will probably use the mailbox the vast majority of the time.
I wanted to eliminate some of the ductwork so I kept it to just a 3" connector. I used 5" steel angle braces that are screwed into the mailbox with self tapping screws. Seems to work pretty good.