Got some answers from the factory regarding the cabin heat exhaust shroud.

In my previous post I had the large clamps that go around the shroud on wrong - they go on the inside and you just drill through the existing holes in the shroud into the clamps.  That's easier!

Also, they say I have to remove the already torqued engine mount bolt to get the shroud on...  Wish I knew that before...  But, I'm going to try to just undo the mounting clamp of the exhaust since it seems like that would also work.  I'll try that tomorrow night and hopefully I'm right.

Apparently there are supplied stainless steel rivets for the shroud assembly, so I'll have to look for those.

They sent a bunch of close-up photos of the exhaust/shroud assembly, so I've added those to the bottom of the Factory Photos - Engine Page.