Built a Ron Tyler inspired Diff mount today. Didn't have any 3" or 1" x 1/4" flat bar, but did have some 6mm x 100mm flat bar, so used that instead. I didn't use Ron's dimensions as my driveline angles are not the same as a JTR build. Overall I got my driveline sitting at 1.9 degrees and the driveline is parallel in the horizontal plane within ~0.1 degrees.
Here are the pictures.
As you can see in the photos, I am going to need to change to a 240z rear mount roll bar.