Thanks for the pics!
Looks like it's coming along. With that wrap-around windshield, it would take a lot of work to lean it back the way I'm testing mine in the edited photo, and it would likely still need to be custom cut. On the other hand the '55 has a long top to begin with so you don't lose all that much by sinking it like you've got it. Mine would look lost in the middle of the Olds body if I did that. It would lose 5 - 6 inches in length for a 2 - 3 inch drop instead of chop. (Look at that 50 Pontiac on HAMB, the 8th page shows a before and after).
Are you channeling the '55? (Looking at the photo where you're adding sections to the driveline tunnel).