for the sake of completeness, link to my dual tcase pics.

yea sean, that is a fixed yoke case. With my project, I actually had both at my disposal. I don't recall the seal being a problem with either, but I choose the fixed yoke due to the shorter snout more material/surface area since I was welding my adapter plate to it.

you can see the difference in the two covers here:
http://www.zu4x.com/albums/album12/IMG_0140.jpg

-Rob