WHOAH I missed that this was a 4spd, now I'm super stoked for you.

(I've always preferred a stick shift. I just slammed an 833 in the Duster 2 days ago and my also buddy completed putting a muncie in his 70 Chevelle this weekend)

Your floors look great too (save for under the back seat area.)

EDIT I'm going back to watch more of the video.
Also I've had good luck with rust removal, My Cuda (front end) and Duster (exhaust manifolds) (even the Dart trunk) project threads cover some methods