I cant help you with that post but I have a hard time believing that can be accomplished with a single hanger. If you have the same Brunswick light that I do I think its over 9' long.
I am looking for a Brunswick light in the New England area and would like to do a similar mount, unfortunately there was no response on the thread to explain how to do it.
That never stopped me before though.
======= edit ========
OK, just went back to the thread below and it looks like the how-to instructions were posted. I missed that the first time around...