Hi Wayne,
You did a nice job with the fireplace installation.
I just picked up my 2011 2900MK and was thinking about doing the same thing, but the water heater enclosure looks like it will interfere with the installation as it is installed directly below the TV set. Is that the way your 2008 is configured?
If so, how did you get the fireplace in there?
How deep (front to back) is your fireplace?
Warren