The exhaust system as not much problem at all. I essentially needed to do three things - replace the flex segment in the downtube, fabricate a "cat eliminator" and fabricate a front support.

Flex Tube

While it's not technically required to replace the flex joint in the downtube, mine was completely separated and unreparable, so I welded in a new stainless flex tube I got off eBay. It's a lot more flexible and will last longer, I believe. Just be sure to measure carefully to get the right size and length for the downtube.

Cat Eliminator

I cut off the 380s exhaust connector right in front of the muffler and welded in a larger diameter tube from the 300D. The larger tube runs into two smaller tubes however the aggregate cross section provides more than enough capacity for the diesel.

I then fabricated a short section of pipe that would join the down tube to the rear section of exhaust.

And finally create a front exhaust hangar bracket from the transmission.

Here's the bracket before installation.

 For anyone working without a welder, this would be an easy task for any muffler shop to handle.